525,082 MECHANICS Mechanics of feeding of the mallard /Anas platyrkynchos L., Aves. Anserifermes/: the ilagual apparatus and the suction-pressure pump meckanism ef straining. [Aut]: G. A.Zweers [et al.] Basel 1977 S.Karffer 8 s.VII, nlb.1. 105,11. Contributions te Vertebrate Evolution vol.