1. Afzelius, K. Apomixis in der Gattung Arnica. Svensk Bot. Tid.30: 572–579. 1936.
2. Akerberc, E. Further studies of the embryo- and endosperm development inPoo pratensis. Hereditas29: 199–201. 1943.
3. Alderman, W. H. Experimental work on self-sterility in the apple. Proc. Am. Soc. Hort. Sci.: 94–101. 1917.
4. Andrew, R. W. et al. Some effects of the waxy and sugary genes on endosperm development in maize. Jour. Agr. Res.69: 355–371. 1944.
5. Armstrong, J. M. Hybridization ofTriticum andAgropyron. I. Crossing results and description of first generation hybrids. Canad. Jour. Res., C,14: 190–202. 1936.