Gaya APA
Nelson, A, L., Folley, K, W.
(1956).
Plane Trigonometry
(
Ketiga)
.
USA:
Harper Collins Business.
Gaya MLA
Nelson, Alfred, L.., Folley, Karl, W..
"Plane Trigonometry".
Ketiga
USA:
Harper Collins Business,
1956.
Teksbook.