S Berentsen, E Ulvestad, R Langholm, K Beiske, H Hjorth-Hansen, W Ghanima, JH Sorbo and GE Tjonnfjord (2006) “Primary chronic cold agglutinin disease: a population based clinical study of 86 patients”, Haematologica. Pavia, Italy, 91(4), pp. 460-466. doi: 10.3324/%x.