Gaya APA

Helmkamp, G, K, &, J, H, W. (1968). Selected Experiments in Organic Chemistry (2). Amerika: W.H. Freeman And Company.

Gaya MLA

Helmkamp, George, K., &, Johnson,, Harry, W.. "Selected Experiments in Organic Chemistry". 2 Amerika: W.H. Freeman And Company, 1968. Text.