1. Archimowitsch, A., 1949: Control of Pollination in Sugar Beet. ? Bot. Rev.15, 613?628.
2. Baker, H. G., 1965: Characteristics and modes of origin of weeds. ? InBaker, H. G. (Ed.): The Genetics of Colonizing Species, 147?172. ? New York: Academic Press.
3. Ehrendorfer, F., 1965: Dispersal mechanisms, genetic systems and colonizing abilities in some flowering plant families. ? InBaker, H. G., (Ed.): The Genetics of Colonizing Species, 331?352. ? New York: Academic Press.
4. Hawthorn, L. R., Pollard, L., 1954: Vegetable and Flower Seed Production. ? New York: Blakiston.
5. Murbeck, Sv., 1921: Beiträge zur Biologie der Wüstenpflanzen, II. ? Lunds Univ. Årsskr.17, 1?52.