Additional reference books from other sources which may be helpful:
Many of these books are out of print but may be available in used bookstores, online or libraries.

• South Africa's Proteaceae, Know Them and Grow Them by Marie Vogt (out of print)
• South African Proteaceae in New Zealand by Lewis Matthews
• Proteas, The Propagation and Production of Proteaceae by Jack Harre (out of print)
• Proteas, A Field Guide to the Proteas of Southern Africa by Tony Rebelo
• The Banksia Book by Alex S. George
• The Protea Book: A guide to cultivated Proteaceae by Lewis Matthews
• Protea by Colin Paterson-Jones
• The Protea Growers Handbook by Lewis Matthews
• The Protea Family in Africa by Colin Paterson-Jones
• Protea in Hawaii by Paul Wood & Ron Dahlquist
• Proteas for Pleasure: How to grow & Identify them by Sima Eliovson
• Proteas of the world by Lewis Matthews & Zoe Carter
• Sasol Proteas: a Field Guide to Proteas by Tony Rebelo & Colin Peterson-Jones
• Proteas in Hawaii by Angela Kay Kepler
• Proteas: Know them and Grow them by Marie Murray Vogts
• Proteas of South Africa by John Rouke
• Growing Proteas by Rob McLennan
• Proteas of South Africa by J. S. Beard & Lara Repley
• Grow Proteas: A Guide to Propagation and Cultivation by Nathaniel Brown