This will not be an exhaustive list, simply bc there's so much sources that I've come across.

To start with;
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=3143311681
That is an important list for this topic too. Many books, especially those by Bryce in that list have aged decades by heavy use from that list. Especially the Atlas by Bryce, in-valuable for many areas of the in-game world. While the book by van den Hout on the Hittite language has been very heavily used for grammar with Hittite unit names.

From the following list The work by Corti, Weeden, Ullmann and Homan have been important sources from the northern Anatolian, while Buzakhar for the Libu desert place names. With Kloekhorst lexicon seeing heavy use for Hittite unit names.
Others:

• Land of Nuhašše by other names
  By Mackey
  
• Various[www.lexilogos.com] by Various
  
• The Hittites - Their Inscriptions and Their History
  By Campbell
  
• Settlement Hierarchy and the Location of Alashiya on Cyprus
  By Armstrong
  
• Canadian Society for Mesopotamian Studies Journal Volumes 14
  By Beaulieu
  
• Luwian Identities - Culture, Language and Religion Between
  Anatolia and the Aegean
  By Mouton, Rutherford, Yakubovich
  
• A Grammar of Akkadian
  by Huehnergard
  
• Proto-Indo-european lexicon
  by Lopez-Menchero
  
• The Hittite Dictionary
  by Güterbock, Hoffner, van den Hout, Goedegebuure
  
• The Hittite Dictionary
  by van den Hout, Goedegebuure
  
• State Archives of Assyria Bulletin
  by Lanfranchi, Ponchia, Fales
  
• Hittite Courtiers and their titles
  by Goetze
  
• Echoes of the Habiru in the Abimelech and Jephthah narratives
  by Garcia
  
• A Grammar of Modern Indo-European
  by Quiles
  
• Lycian and Phrygian names
  by Arkwright
  
• Wheels in a land of camels: another look at the
  chariot in Arabia
  by MacDonald
  
• Ur in the Kassite Period
  by Clayden
  
• Introduction to Akkadian
  by Snell
  
• Buried Amazigh place names in the Libyan Desert
  by Buzakhar
  
• Anatolian Names in -wiya and the Structure of Empire Luwian Onomastics
  by Yakubovich
  
• Is Sarpedon a Bronze Age Anatolian personal name or a Job description?
  by Durnford
  
• The North: Hanhana, Hattina, Ištahara, Hakpiš, Nerik, Zalpuwa, Tummana, Pala and the Hulana River Land (same as below)
  by Corti
  
• Hittite Landscape and Geography (same as above)
  by Weeden, Ullmann and Homan
  Note: the document on academia says Corti, but the actual document say Weeden etc.
  
• Hittite Vocabulary: An Anatolian Appendix to Buck’s Dictionary of Selected Synonyms in the Principal Indo-European Languages
  by Weeks
  
• Anthropology of a Frontier Zone: Hittite-Kaska Relations in Late Bronze Age North-Central Anatolia
  by Glatz and Matthiews
  
• The Nomes of Ancient Egypt
  by Leeman
  
• The Hittite Inherited Lexicon
  by Kloekhorst
  
• War at Sea: The Advent of Naval Combat in the Late Bronze-Early Iron Age Eastern Mediterranean
  by Emanuel
  
• Hattusili: The Hittite Prince who stole an Empire
  by Bryce
  
• Hurrian and Urartian basic lexicon
  by Forni
  
• Economic Complexity in the Ancient Near East
  by Mynarova and Alivernini
  
• The Making of Hittite Imperial Landscapes: Territoriality and Balance of Power in South-Central Anatolia during the Late Bronze Age
  by Alvise Matessi
  
• Bible (for some naming in Canaan)
  by various scribes
  
• Organization, Representation, and Symbols of Power in the Ancient Near East
  by Gernot Wilhelm
  
• The City of Emar among the Late Bronze Age Empires History, Landscape, and Society
  by Lorenzo d’Alfonso, Yoram Cohen and Dietrich Sürenhagen
  
• PU-RO, PA-KI-JA-NA/-NE, and the sanctuary of Poseidon at Pylos
  by Montecchi
  
• A Companion to Linear B: Mycenaean Greek Texts and their World
  by Duhoux and Davies
  
• Euboea, Athens, Thebes and Kadmos: The Implications of the Linear B References
  by Palaima
  
• Some comments on the Late Bronze Age process in Erzurum and the adjacent region
  by Işıklı
  
• The Eastern Provinces of Urartu and the Beginning of History in Iranian Azerbajian
  by Salvini
  
• The Assyrian Itineraries in the Zagros during the reign of Sargon II (6th and 8th campaigns) and the question about the correlation between Toponymy and Geography
  by Tourovets
  
• The Oxford Bible Atlas
  by Adrian Curtis
  
• The Kingdom of Mycenae: A Great Kingdom in the Late Bronze Age Aegean
  by Kelder
  
• Essays on Ancient Israel in it's Near Eastern Context
  by Amit, Ben Zvi, Finkelstein, Lipschits
  
• Byblos in the Late Bronze Age: Interactions between the Levantine and Egyptian Worlds
  by Kilani
  
• Carchemish[www.hittitemonuments.com]
  by Hittite monuments
  
• A Phoenician-Punic Grammar
  by Krahmalkov
  
• Linear B lexicon
  by Tselentis Gree
  
• A Tentative Grammar of Mycenaean Greek
  by Vilborg
  
• Etymylogical Dictionary of Greek
  by Beekes
  
• Aspects of the Historical Geography of Northeastern Syria from Middle Assyrian to Neo-Assyrian Times
  by Röllig
  
• "They were thr on land, others at Sea..." The etymylogy of the Egyptian term for Sea-Peoples
  by Ben-Dor Evian
  
• Making Mittani Assyrian
  by Koliński
  
• The Geography of the Borsippa Region
  by Zadok
  
• Excavations at Dura-Europos 1928–1937
  by James
  
• New Light on the Land of Sūḫu
  by Edmonds
  
• Water for Assyria
  by Kühne
  
• Dūr-Katlimmu, an Alleged Neo-Assyrian Library Text, Ḫana, and the Early History of Dura-
  Europos ISSN 0989-5671
  by NOTES BRÈVES
  
• Αthens and Attica in Prehistory
  by Papadimitriou, Wright, Fachard, Polychronakou-Sgouritsa, Andrikou
  
• SOCIOLINGUISTICS OF THE LUVIAN LANGUAGE
  by Yakubovich
  
• Ḫinduwa: Kindye oder Kandyba?
  by Simon
  
• The Story of a Forgotten Kingdom? Survey Archaeology and the Historical Geography of
  central Western Anatolia in the Second Millennium BC
  by Roosevelt, Luke
  
• The Aegean–Anatolian Interface: Overview of the Late Bronze and Iron Age Evidence (ca. 1400–700 bce)
  by Matessi
  
• Archaeology at the Frontiers: Excavating a Provincial Capital of the Assyrian Empire
  by Matney, MacGinnis
  
• Was the Reign of Tawosret in Fact Successful?
  by van Cleve
  
• The Western Marmarica Coastal Survey, Libya
  by Hulin
  
• The Oldest Berber Text(s)? Egyptian Evidence for the Ancient Libyan Language(s)
  by Silvestri
  
• talugaeš witteš
  by Cammarosano, Devecchi, Viano
  
• Economic Complexity in the Ancient Near East
  by Mynářová, Alivernini
  
• A Master of Secrets in the Chamber of Darkness
  by Scalf, Muhs
  
• Kassite Babylonia
  by Paulus
  
• Empire and Ethnicity: A Social History of Deportation in Assyria and Karduniaš during the First Millennium BCE
  by Spunaugle
  
• Assyrian Glossary
  by Talbot
  
• List of Neo-Assyrian Cuneiform Signs
  by Borger
  
• Hurrian
  by Wilhelm
  
• Indo-Iranian personal names in Mitanni: A source for cultural reconstruction
  by Gentile
  
• The Syrian and the Anatolian: Cultural and political frontiers in the post-Hittite Eastern Mediterranean (ca. 1200-700 BCE)
  by Matessi
  
• The Trojan War as Military History
  by Kambouris
  
• The Geography of the Hittite Empire and the Distribution of Luwian Hieroglyphic Seals
  by Woudhuizen
  
• The Trojan War: Is There Truth behind the Legend?
  by Bryce
  
• Imagining the Past
  by Manassa
  
• Byblos in the Late Bronze Age: Interactions between the Levantine and Egyptian Worlds
  by Kilani
  
• Brill’s Companion to Warfare in the Bronze Age Aegean
  by Kvapil, Shelton

Use of sources:
I think I've not used any one source verbatim 1:1, this is simply bc many of these sources contradict each other. So to makes heads or tales out of everything I've had to pick and choose on what information to use where and thus what makes the most sense to me. Thus this mod is in the end my interpretation on things.
With Open Street maps and Google Maps being significant when hunting for really obscure locations and Wikipedia having filled in many blanks by having unnamed volunteers who posted information leading to an in-game place name, either via direct information or via provided sources. While Wikimedia Commons serving as the bulk of picture source material used in this mod with many unnamed volunteers.

Some Wikimedia Commons User's Work I've used; (Not everyone mentioned, simply bc volume is so big and hard to remember every influence, same as with the research papers, this is thus my best effort :) )

• Library Guy[commons.wikimedia.org]
  
• Nancy T. de Grummond
  
• Jeff Dahl[commons.wikimedia.org]
  
• Eternal Space[commons.wikimedia.org]
  
• FalconKnight[commons.wikimedia.org]
  
• Inowen[commons.wikimedia.org]
  
• Furfur[commons.wikimedia.org]
  
• Rh0809[commons.wikimedia.org]
  
• Loic Poivet[thenounproject.com]
  
• Fahrul Oktaviana[thenounproject.com]
  
• Gökhan Can Wikipedia
  
• Some listed as 'Unknown artist'
  
• George Bit Atanus
  
• Adam Izgin
  
• Goodarz Irani[commons.wikimedia.org]
  
• CdnMCG[commons.wikimedia.org]
  
• Austen Henry Layard

Beyond this much of the imagery is also painted by me or otherwise heavily edited.