Gaya APA
Lubis, A., R., B. (2006).
The Merck Index four edition (four edition ( 4 )).
Whitehouse Saton. NJ.USA:
Merck & Co. Inc.
Gaya MLA
Lubis, A., R., B..
The Merck Index four edition.
four edition ( 4 )
Whitehouse Saton. NJ.USA:
Merck & Co. Inc,
2006.
Text.