Hristova, L., Kovachev, D., Spassov, N. 2002. The Hipparions (Equidae, Mammalia) from the Upper Miocene locality Hadzhidimovo, SW Bulgaria. Rev. Bulg. Geol. Society, 63, 1—3, 89—98. (in Bulgarian, English abstract)
Hristova, L., Kovachev, D., Spassov, N., 2003. Hipparion brachypus Hensel, 1862 from the Late Miocene of Hadzhidimovo, Southwestern Bulgaria. Comptes rendus de l’Academie bulgare des Sciences, 56 (2): 77—84.
Hristova, L., Kovachev, D., 2005. Notes on taxonomy on the Middle Turolian hipparions from localities near Kalimantsi village. Mathematics and natural sciences. Proceedings of the International scientific conference 8—11.06.2005. South-West University, Blagoevgrad, V. 2., 180—184.
Hristova, L., Spassov, N., 2005. Taxonomy and Ecology of the late Miocene Hipparions of Bulgaria: contribution to the questions of the Balkans’ Turolian stratigraphy and environment changes. Abstract on Annual NECLIME Meeting, Sofia, October 1—4, 2005.
Hristova, L. 2009. Ontogeny and variability in the cheek region of hipparions from the Late Miocene locality Hadzhidimovo-1, Southwest Bulgaria. Rivista Italiana di Paleontologia e Stratigraphia, 115, 1, 123—130.