complete book of U.S. sniping / Peter R. Senich Sniper : a history of the US marksman / Martin Pegler Ordnance maintenance u.s. rifles, cal..30 M1, M1c (sniper's) and M1d (sniper's) - USA Technical Manual, TM 9-1275 marine corps museum monograph series U.S. Marine Corps Marksmanship Badges from 1912 to the present / by Michael D. Visconage U.S. army sniper training manual : TC 23-14
