1. The Royal Dutch Shell Petroleum Company 1890–1950, Diamond Jubilee Book,, Nijgh and Van Ditmar NV, The Hague, 1950, p. 75.
2. The Royal Dutch Shell Petroleum Company 1890–1950, Diamond Jubilee Book, Nijgh and Van Ditmar NV, The Hague, 1950, p. 79.
3. The Royal Dutch Shell Petroleum Company 1890–1950, Diamond Jubilee Book, Nijgh and Van Ditmar NV, The Hague, 1950, p. 82.
4. S. H. McAllister, Refinery Nat Gasoline Mfr, (Nov 1937) 493.
5. K. G, Mackenzie, Refinery Nat Gasoline Mfr, (Nov 1939) 494.