Gaya APA
Niven, I., M. (1991).
AN INTRODUCTION TO THE THEORY OF NUMBER FIFTH EDITION (fifth Edition).
New York:
WILEY.
Gaya MLA
Niven, Ivan, Morton.
"AN INTRODUCTION TO THE THEORY OF NUMBER FIFTH EDITION".
fifth Edition
New York:
WILEY,
1991.
Buku Inti.