Trade promotion series
G.P.O
Microform（Microfilm Reel）
by W. Rodney Long
U.S. G.P.O. 1939 Trade promotion series no. 196
Available at 4 libraries
by Jesse E. Saugstad
U.S. Govt. Print. Off. 1932 Trade promotion series no. 129
Available at 8 libraries
by M.M. Smith and J.N. Taylor
U.S. Govt. Print. Office 1929 Trade promotion series no. 86
Available at 1 libraries