1.
 |  | Title: Threatened Birds of the Americas (The Icbp/Iucn Red Data Book ; Pt. 2) by L.P. Gonzaga, N. Krabbe, A. Madrono Nieto, N. J. Collar, T. A. Parker, L. G. Naranjo ISBN: 1560982675 Publisher: Smithsonian Institution Press Pub. Date: March, 1993 List Price: $50.00 Amazon.com Price: $50.00 |
2.
 |  | Title: Threatened Birds of Africa and Related Islands: The Icbp/Iucn Red Data Book, Part 1 by N. J. Collar, S. N. Stuart ISBN: 1560982667 Publisher: Smithsonian Institution Press Pub. Date: June, 1993 List Price: $50.00 Amazon.com Price: $50.00 |
3.
 |  | Title: Threatened birds of the Philippines : the Haribon Foundation/BirdLife International Red data book by N. J. Collar ISBN: 9715693342 Publisher: Bookmark Pub. Date: 1999
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4.
 |  | Title: Birds to Watch 2: The World List of Threatened Birds (Birdlife Conservation, No 4) by N. J. Collar, M. J. Crosby, International Union for Conservation of Nature and Natural Resources, Birdlife International, A. J. Stattersfield ISBN: 1560985283 Publisher: Smithsonian Institution Press Pub. Date: August, 1995 List Price: $45.00 Amazon.com Price: $45.00 |
5.
 |  | Title: Birds to Watch by N.J. Collar ISBN: 0946888302 Publisher: BirdLife International Pub. Date: 1998
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6.
 |  | Title: Key Forests for Threatened Birds in Africa by N. J. Collar ISBN: 0946888159 Publisher: International Pub. Date: January, 1988
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