Oram, R. N., Ferreira, V., Culvenor, R. A., Hopkins, A. A., Stewart, A., (2009). Crop & Pasture Science 60(1), 1-15. CSIRO Publishing, Collingwood, Australia. English language
Øverli, Ø., Páll, M., Borg, B., Jobling, M., Winberg, S., (2001). Proceedings of the Royal Society of London. Series B, Biological Sciences 268(1474), 1411-1415. Royal Society, London, UK. English language
Kalton, R. R., Richardson, P., Shields, J., (1989). Crop Science 29(5), 1327-1328. English language
Kalton, R. R., Shields, J., Richardson, P., (1989). Crop Science 29(5), 1327. English language
Sachs, A. P. W., Coulman, B. E., (1983). Crop Science 23(6), 1041-1044. English language