M.  Kalafati?, Kopjar, N., Zrna, G., Zupan, I., Kovacevi?, G., and Franjevi?, D., ?Karyological analysis of two allopatric populations of planarian Polycelis felina (Daly.) in Croatia?, Folia Biol (Krakow), vol. 52, no. 1-2, pp. 131-3, 2004.

M.  Kalafati?, Kopjar, N., and Besendorfer, V., ?The impairments of neoblast division in regenerating planarian Polycelis felina (Daly.) caused by in vitro treatment with cadmium sulfate?, Toxicol In Vitro, vol. 18, no. 1, pp. 99-107, 2004.

C. E.  Cook, Jimenez, E., Akam, M., and Salo, E., ?The Hox gene complement of acoel flatworms, a basal bilaterian clade?, vol. 6, 2004.

T.  Inoue, Kumamoto, H., Okamoto, K., Umesono, Y., Sakai, M., and A. Alvarado, S., ?Morphological and functional recovery of the planarian photosensing system during head regeneration?, vol. 21, 2004.

N. M.  de Campos-Velho, Lopes, K. A., and Hauser, J., ?Morphometry of the eyes in regenerant of genus Dugesia (Platyhelminthes, Turbellaria, Dugesiidae)?, Brazilian journal of biology, vol. 64, pp. 1-9, 2004.

M.  Charni, Harrath, A. Halim, Sluys, R., Tekaya, S., and Zghal, F., ?The freshwater planarian Dugesia sicula Lepori, 1948 (Platyhelminthes, Tricladida) in Tunisia: ecology, karyology, and morphology?, Hydrobiologia, vol. 517, pp. 161-170, 2004.

S.  Ishida, Yoshida, W., Nishitani, S., and Teshirogi, W., ?New karyotype of the freshwater planarian Seidlia auriculata collected from shirakami mountains?, Zoological Science, vol. 21, p. 1345, 2004.