This is actually hard question, as there is huge potential for the sources of such things:
Hardcovers include:
Advanced Class Guide(ACG?) Horror Adventures(HA?), Monster/NPC/Villain Codex, Ultimate Wilderness(UW), Ultimate Intrigue(UI), Ultimate Combat?(UC). Mythic Adventures, Occult Adventures.
Planar adventures was quite late in development so probably can be skipped.
I am not aware if there exists comprehensive list of shortcuts.
Probably companion books such as Adventurers Armory 1/2(I saw stat block with AA2 spell I think, but could have confused with other edition), Campaign Settings. Book of the damned had it's own shortcut afair. Somewhere. Or maybe I am wrong.
Ah and Adventures Paths can refer to previous books in the series:D, but I've just checked and at least in Reign of Winter standard is to use * instead of shortcut.
I will do some googling and possibly try to compile some master list. Might take a while.
Final list based on https://docs.google.com/spreadsheets...8c/edit#gid=0:
Abbreviation - Book
UM - Ultimate Magic
APG - Advanced Players Guide
OA - Occult Adventures
UI - Ultimate Intrigue
ISWG - Inner Sea World Guide
UW - Ultimate Wilderness
ARG - Advanced Race Guide
HA - Horror Adventures
UC - Ultimate Combat
MA - Mythic Adventures
ACG - Advanced Class Guide
AP75 - Adventure path #75, exists only once in this excel so might be problem with excel.
MC - Monster Codex
D - Domain
M - Mythic variant of a spell