Basso, A. C.; Esper, C. R. Isolation and Ultrastructural Characterization of Preantral Follicles in the Nelore Breed Cows (Bos Taurus Indicus). Braz. J. Vet. Res. Anim. Sci. 2002, 39 (6), 311-319. https://doi.org/10.1590/S1413-95962002000600007.