1. Pohjakallio, O., and Karhuvaara, L., Maataloust. Aikakausk, 32, 73 (1960).
2. Harland, S. C., and King, E., Heredity, 11, 287 (1957).
3. Mercado, jun., A. C., and Lantican, R. M., Philipp. Agric., 45, 235 (1961).
4. Al'smik, P. I., Kartofel, Moskva, No. 4, 47 (1957).