Institut pochvovedeni︠i︡a i fotosinteza (Akademi︠i︡a nauk SSSR), Nauchnyĭ ︠t︡sentr plodorodi︠i︡a pochv (Czechoslovakia), Hraško, J., & Kefeli, V. I. (1990). Povedenie poll︠i︡utantov v pochvakh i landshaftakh: Sbornik nauchnykh trudov. Nauch. ︠t︡sentr biologicheskikh issl. AN SSSR.

Institut pochvovedeni︠i︡a i fotosinteza (Akademi︠i︡a nauk SSSR), Nauchnyĭ ︠t︡sentr plodorodi︠i︡a pochv (Czechoslovakia), Juraj Hraško, and V. I. Kefeli. Povedenie Poll︠i︡utantov V Pochvakh I Landshaftakh: Sbornik Nauchnykh Trudov. Pushchino: Nauch. ︠t︡sentr biologicheskikh issl. AN SSSR, 1990.

Institut pochvovedeni︠i︡a i fotosinteza (Akademi︠i︡a nauk SSSR), et al. Povedenie Poll︠i︡utantov V Pochvakh I Landshaftakh: Sbornik Nauchnykh Trudov. Nauch. ︠t︡sentr biologicheskikh issl. AN SSSR, 1990.