Haurongo: Butler, Joseph rāua ko Butler, William James
He whakaaturanga anō
Rārangi pukapuka
Obit. [J. Butler]. New Zealand National Review. 15 Oct. 1934: 61--62
Obit. [W. J. Butler]. New Zealand National Review. 15 Dec. 1932: 55--56
Roche, M. M. History of forestry. Wellington, 1990
Ward, W. C. Dominion Sawmillers' Federation Incorporated: 50 years…a history. Wellington, 1990