3. Wagner (1889), Aphanipterologische Studien. Hor. Soc. Ent. Ross. Vol. XXIII., p. 199; (1893) Vol. XXVII., p. 347; (1898) Vol. XXXI., p. 539; (1902) Vol. XXXV., p. 17; (1903) Vol. XXXVI., p. 125.
A series of learned papers by a professor at the Russian University of Kieff. He has also written in Russian.
4. Dampf (1907), Die Ost-und Westpreussische Flohfauna. Schriften der Physik.-ökonom. Gesellschaft zu Königsberg-i-Pr., XLVIII. Jahrgang, p. 388.
Contains an excellent general account of our present knowledge of fleas. Short Bibliography.
5. Dampf (1910), Palæaeopsylla Klebsiana n. sp. ein fossiler Floh aus dem baltischen Bernstein. Schriften der Physik.-ökonom. Gesellschaft zu Königsberg-i-Pr., LI. Jahrgang, II. 248.
Good plates of the fossil flea in amber.
6. Oudemans (1909), Neue Ansichten über die Morphologie des Flohkopfes sowie über die Ontogenie, Phylogenie und Systematik der Flöhe. Novitates Zoologicæ, Vol. 16, p. 133.
Suggests a new classification based on the morphology of the head, viz. (1) Integricipita; (2) Fracticipita. By the chief authority on fleas in the Netherlands. He has also written numerous papers in Dutch.
7. Jordan and Rothschild (1908), Revision of the non-combed eyed Siphonaptera. Parasitology, Vol. I., p. 1. Plates. Bibliography.