Tube Substitution Handbook 11th Edition January 1968 Pocket Edition

Tube Substitution Handbook Vol. 9

VINTAGE 1960 VINTAGE TUBE SUBSTITUTION HANDBOOK NO. 16

TV/Radio Tube Substitution Handbook by Howard Sams 1971

Radio Shack Tube Substitution Handbook by Sams 1977 111 Pages, Excellent

1968 Tube Substitution Handbook No.11

VINTAGE TUBE SUBSTITUTION HANDBOOK No. 21 Howard Sams Engineering

Vtg Tube Substitution Handbook, No. 10 authored by Howard W. Sams, Eng. Staff