@book{bhlitem57714, title = {The Bell System technical journal }, volume = {v. 20 (1941)}, copyright = {NOT_IN_COPYRIGHT}, url = {https://www.biodiversitylibrary.org/item/57714}, note = {https://www.biodiversitylibrary.org/bibliography/18181}, publisher = {Short Hills, N.J., etc, American Telephone and Telegraph Co, }, author = {American Telephone and Telegraph Company.}, year = {1941}, pages = {478}, keywords = {Communication|Electric engineering|Electronics|Periodicals|Science|Technology|Telecommunication|}, }