APA aipamena

National Productivity Board and National Productivity Association. (1982). Productivity digest (Singapore). Singapore: National Productivity Board and National Productivity Association.

Chicago Style aipamena

National Productivity Board and National Productivity Association. Productivity Digest (Singapore). Singapore: National Productivity Board and National Productivity Association, 1982.

MLA aipamena

National Productivity Board and National Productivity Association. Productivity Digest (Singapore). Singapore: National Productivity Board and National Productivity Association, 1982.