Discussing "Non-Resident Training Course" (NRTC) library of the US Navy

By searching Google for "NAVEDTRA 14139", you will likely find the featured "Basic Math" NRTC there. Or, even on Amazon at: https://www.amazon.com/Navy-Mathematics-NAVEDTRA-Nonresident-Training/dp/1304189821 .

"Global Security" has a page regarding more technical fields of the Navy and a catalog of those NRTCs here: https://www.globalsecurity.org/military/library/policy/navy/nrtc/index.html .

There is also an official, albeit from 1999, Naval publication regarding NRTCs that existed: https://apps.dtic.mil/sti/citations/ADA359532 .