The electric telegraph - a manual of complete instruction in the principles, mechanism, and practice of the art of sending and receiving telegraphic messages, including multiplex and wireless systems of transmission

Förlag	År	Ort	Om boken	ISBN
American School of Correspondence	1908	USA, Chicago	99, 38 sidor. : ill.
McGraw Publ. Co.	1905	USA, New York	xi, 299 sidor. ill.