The leading historian Keith Sorrenson has collected in three volumes the complete correspondence (174 letters in all) between two distinguished twentieth-century Maori scholars and statesmen, Sir Apirana Ngata and Sir Peter Buck (Te Rangi Hiroa). Volume Three of Na to Hoa Aroha also contains an epilogue and an index to the works. 'The letters confirm that each man was indeed a totara tree of some magnificence and that each was a tree that stood alone. Even today such trees remain rare,' writes Hirini Moko Mead.