Die papageien, monographisch bearbeitet.

Leiden: E J Brill, 1867-1868.
Octavo, three volumes 1557 pp. one handcoloured lithographic distribution map, six (one folded plain and five handcoloured) lithographed plates and some folded tables. Modern green half morocco and marbled boards, marbled edges, a very good set.

The first true monograph published on parrots.

Anker 142; Nissen IVB, 314; Zimmer I, 220; Wood 341.