APA
"NATIONAL BUREAU OF ECONOMIC RESEARCH I., "NATIONAL BUREAU OF ECONOMIC RESEARCH I., . (1971). 51st annual report 1971. New: York NBER.
Chicago
"NATIONAL BUREAU OF ECONOMIC RESEARCH INC.", "NATIONAL BUREAU OF ECONOMIC RESEARCH INC.", . 1971. 51st annual report 1971. New: York NBER.
Harvard
"NATIONAL BUREAU OF ECONOMIC RESEARCH I., "NATIONAL BUREAU OF ECONOMIC RESEARCH I., . (1971). 51st annual report 1971. New: York NBER.
MLA
"NATIONAL BUREAU OF ECONOMIC RESEARCH INC.", "NATIONAL BUREAU OF ECONOMIC RESEARCH INC.", . 51st annual report 1971. New: York NBER. 1971.
