EL-KASSABY, Yousry A. Clonal-row vs. random seed orchard designs: mating pattern and seed yield of western hemlock (Tsuga heterophylla (Raf.) Sarg.). In Forest genetics : international journal of forest genetics. - Arbora Publishers : Zvolen. ISSN 1335-048X, 2003, vol. 10, no. 2, s. 121-127.