http://vanillagaming.org/forum/index.php?topic=17332.0
https://www.barrens.chat/viewtopic.php?f=7&t=83
https://www.wow-professions.com/guides/vanilla-engineering-leveling
https://legacy-wow.com/engineering-1-300/
https://www.nightelfmohawk.com/guides/classic-wow-engineering-guide-1-300/