Battle Order now has a Resources page that will include direct links to primary and secondary sources. These will eventually include a plethora of military manuals, TO&Es, and academic papers (some of which aren't available online at all or are hard to access for an English-only speaker). These will always be free to access.
With the inaugural post, 36 military manuals and 1 academic papers were added today. One was from the Cold War period while the remainder were from the Post-Cold War period. Broken down into nationalities:
1 El Salvadorian