1. The History of Mathematical Tables
2. Napier, J., [Rabdologiæ], Andreas Hart, Edinburgi (1617).
3. On the history of Gunter’s scale and the slide rule during the seventeenth century;Cajori,1920
4. Infra Red Telegraphy and Telephony
5. Vogeler, A. R., [The odyssey of a scientist: the career of Dr. Edgar Kutzscher in Germany and America], California State University, Fullerton, California (1986).