George Gray's most important publication was his Genera of Birds (1844–49), illustrated by David William Mitchell and Joseph Wolf, which included 46,000 references.
Негово најважно научно дело е was his Genera of Birds („Родови птици“, 1844–49), илустрирано од Дејвид Вилијам Мичел и Јозеф Волф, во кое има 46.000 наводи.