Jolley, E. (1992). Introduction to telephony and telegraphy. Y.P Chopra.
Lua i Stíl Chicago (17ú heag.)Jolley, E.H. Introduction to Telephony and Telegraphy. Allahabad: Y.P Chopra, 1992.
Lua MLA (9ú heag.)Jolley, E.H. Introduction to Telephony and Telegraphy. Y.P Chopra, 1992.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.