1
Published: 1936
Superior document: Bell telephone system B-962
2
Published: 1930
Superior document: Bell telephone system B-500
3
Published: 1928
Superior document: Reprint / Bell Telephone Laboratories B-288
4
Published: 1933
Superior document: Bell telephone system B-749
5
Published: 1935
Superior document: Bell telephone system B-851
6
Published: 1935
Superior document: Bell telephone system B-850