"Detailed well illustrated hardcover reference book on one of the trickiest realms of bird identification: gulls. Includes many real world photos illustrating gulls in all plumages (all stages from juvenile to adult and breeding/nonbreeding)."
"The ultimate ornithology text by the world's leading authority on ornithology. This 1200+ page book covers all aspects of bird biology in detail. Very readable; no biology degree needed to read this."