Firstly the entry on the Hyacinthine Macaw in Greene's Parrots in Captivity and then excerpts from Len Hill's book on Birdland

I am now putting on interesting early information on the blue macaws in aviculture. This is almost historical and may be put in both sections. Firstly the entry on the Hyacinthine Macaw in Greene's Parrots in Captivity and then excerpts from Len Hill's book on Birdland published in 1976.