https://upload.wikimedia.org/wikipedia/commons/9/90/TM_31-210_Improvised_Munitions_Handbook_-_1969_%28v4.0_Extended_Version%29.pdf
https://trueprepper.com/wp-content/uploads/2022/11/TM-31-210-Improvised-Munitions-Handbook.pdf
https://primitivepursuits.com/wp-content/uploads/2020/09/part-iv-bow-making-e-book.pdf
https://primitivepursuits.com/wp-content/uploads/2020/09/part-iii-bow-making.pdf
https://jan.ucc.nau.edu/tct/tanning.pdf
https://tra.extension.colostate.edu/wp-content/uploads/sites/9/2017/05/25.TanningLeather2.pdf
http://www.survivorlibrary.com/library/practical_tanning_1922.pdf