Global public telephone service 1958
1959 ◽
Vol 7
(2)
◽
pp. 115-120
1954 ◽
Vol 2
(3)
◽
pp. 93-100
Transactions of the American Institute of Electrical Engineers Part I Communication and Electronics
◽
1960 ◽
Vol 78
(6)
◽
pp. 811-817
1948 ◽
Vol 36
(9)
◽
pp. 1146-1152
◽
1899 ◽
Vol 48
(1228supp)
◽
pp. 19688-19689