Gaya APA
Swanson, C, P., Stallcup, J, G. (1989).
Illustrated changes of the 1990 NEC .
Illinois:
Illinois: American Technical; 1989.
Gaya MLA
Swanson, Carl, P.., Stallcup, James, G..
"Illustrated changes of the 1990 NEC".
Illinois:
Illinois: American Technical; 1989,
1989.
Text.