Mechanical drawing for high schools by Berthe E. Spink, Percy H. Sloan, Albert W. Evans, Carl Durand, Fred W. Zimmermann.Berthe E. Spink1910EN
Constructive drawing for secondary schools, by Berthe E. Spink, Percy H. Sloan, Albert W. Evans, Carl Durand, Fred W. Zimmermann.Berthe E. Spink1915EN