1. Bruun, H. G. (1932): Cytological Studies inPrimula with special reference to the relations between the kariology and taxonomy of the genus. Symb. Bot. Upsl.,1, 1?239.
2. Darlington, C. D. (1932). Meiosis inAgapanthus undKniphofia. Cytologia,4, 229?240.
3. ? (1937): Recent advances in Cytology, 2nd ed., J. and A. Churchill, London.
4. ? andLa Cour (1938): Differential reactivity of the chromosomes. Ann. of Bot. N. S.,2, 615?625.
5. Dermen, H. (1933): Origin and behavior of the Nucleolus in plants. J. Arnold Arboret,14, 282?323.