APA
NATIONAL-STANDARD DUNCAN LIMITED, NATIONAL-STANDARD DUNCAN LIMITED, . (1990). Annual report 1979-80. Calcutta: National Standard Duncan.
Chicago
NATIONAL-STANDARD DUNCAN LIMITED, NATIONAL-STANDARD DUNCAN LIMITED, . 1990. Annual report 1979-80. Calcutta: National Standard Duncan.
Harvard
NATIONAL-STANDARD DUNCAN LIMITED, NATIONAL-STANDARD DUNCAN LIMITED, . (1990). Annual report 1979-80. Calcutta: National Standard Duncan.
MLA
NATIONAL-STANDARD DUNCAN LIMITED, NATIONAL-STANDARD DUNCAN LIMITED, . Annual report 1979-80. Calcutta: National Standard Duncan. 1990.
