Gaya APA

Herman, S, L., Sparkman, B, L. (2006). Electricity & Controls for HVAC/R 6 th Edition . USA: Delmar Cengage Learning.

Gaya MLA

Herman, Stephen, L.., Sparkman, Bennie, L.. "Electricity & Controls for HVAC/R 6 th Edition". USA: Delmar Cengage Learning, 2006. Text.