1. Dennis, B. and Helgadóttir, Å. Breeding herbage species for northern Scandinavia. Natural variation and breeding for adaption. pp.169–177. Proceedings of the Eucarpia Fodder Crops Section Meeting, Lusignan, France
2. Modified joint regression analysis for incomplete variety × environment data
3. The analysis of adaptation in a plant-breeding programme
4. Hay, R. K. M. and Heide, O. M. The response of high-latitude Norwegian grass cultivars to long photoperiods and cool temperatures. The impact of climate on grass production and quality. Edited by: Riley, H. and Skjelvåg, A. O. pp.46–50. Proceedings of the 10th General Meeting of the European Grassland Federation, Ås, Norway