. . "Coucous." . . . . . . "Birds fighting. Experimental studies of the aggressive displays of some birds, etc"@en . "Birds fighting, experimental studies of the aggressive displays of some birds"@en . "Birds fighting, experimental studies of the aggressive displays of some birds" . . . . . . . . . . . . . . . "Birds fighting : experimental studies of the aggressive displays of some birds" . . "Birds fighting. Experimental studies of the aggressive displays of some birds. [With plates.]"@en . "Birds fighting : Experimental studies of the aggressive displays of some birds" . . . "Oiseaux Moeurs et comportement." . .