APA Style
Buletin Perkebunan Vol. 21 No. 1 April 1990. (1990).
Medan:
KSU RISPA Medan.
Chicago Style
Buletin Perkebunan Vol. 21 No. 1 April 1990.
1.
Medan:
KSU RISPA Medan,
1990.
Hard Copy.
MLA Style
Buletin Perkebunan Vol. 21 No. 1 April 1990.
1.
Medan:
KSU RISPA Medan,
1990.
Hard Copy.
Turabian Style
Buletin Perkebunan Vol. 21 No. 1 April 1990.
Medan:
KSU RISPA Medan,
1990.
Hard Copy.