Hey, what's in BattleTech's Appendix N?

While searching about for intersting stuff on the BattleTechVerse I found this forum thread, "The moment Battletech jumped the Shark."  That discussion quickly suffered topic drift and wound up focused on Lynn Minmay and the power of song.  But what I think to be much more interesting is the bit of the opening post that says,

With those old authors, you get the sense they actually thought a minute about how mercenary units might work. It was a primary derivative work, derived from lots of reading history books and non-fiction books on military.   The "Northwind Highlanders" as depicted in the nineties book OTOH are a romanticistic wish fulfillment of the author, based on reading Battletech novels and Battletech sourcebooks AND misinterpreting them.

I don't want to be in that second catagory, so if BattleTech had an Appendix N: Inspirational and Educational Reading then what would be in it?  Name some non-fiction books... oh, why discriminate?  Can you name any books (whether non-fiction, fiction, colouring, pop-up or scratch-n-sniff, but under no circumstances BattleTech) which ought be included for a BattleTech bibliography?

Really, I don't know.  That's why I'm posing the question.