See Chambers's autobiography, Witness (1952, repr. 1983); A. Cooke, A Generation on Trial (1950, 2d ed. 1952); R. Seth, The Sleeping Truth: The Hiss-Chambers Affair Reappraised (1968); A. Weinstein, Perjury: The Hiss-Chambers Case (1978); S. Tanenhaus, Whittaker Chambers (1997).
In 1913, he established a partnership with his two sons, Ronald and James, based in Wellington. The business became a limited liability company in 1937, with third-generation Whittakers still the sole shareholders in the company. In 1992 the company formed J.H. Whittaker Australia Ltd.
The company's marketing phrases include "Good honest chocolate" and "A passion for chocolate since 1896". Nationally, the company supports motor and equestrian sports.