Gaya APA

Helmkamp, G, K., Johnson, H, W, J. (1964). Selected experiments in organic chemistry. (1964). : San Francisco : W.H. Freeman and Co.,.

Gaya MLA

Helmkamp, George, K.., Johnson, Harry, W.,, Jr.. "Selected experiments in organic chemistry.". 1964 : San Francisco : W.H. Freeman and Co.,, 1964. Text.