Das, P. N. (1990). Introduction to manual telephony (5th ed.). Modern Book Agency.
Chicago Edition CitationDas, P. N. Introduction to Manual Telephony. 5th ed. Calcutta: Modern Book Agency, 1990.
MLA Edition CitationDas, P. N. Introduction to Manual Telephony. 5th ed. Modern Book Agency, 1990.
Warning: These citations may not always be 100% accurate.