Jelaskan Tempo ogé dari Alexander Graham Bell dalam bahasa sunda

Bell Homestead, National Historic Site

Alexander Bell.com - Telecom Pionneers by Phonebook of the World.com

Biantara Bell  di hareupeun American Association for the Advancement of Science di Boston dina ping 27 Agustus 1880, mintonkeun fotopon. Dimuat kalayan judul "On the Production and Reproduction of Sound by Light" dina American Journal of Sciences, Third Series, vol. XX, #118, Oktober 1880, kaca 305 - 324; sarta "Selenium and the Photophone" dina majalah Nature, Séptember 1880