Staaf J, Akerström T, Ljungström V, Larsson S, Karlsson T, Skogseid B, Bergsten P. Lakartidningen December 31, 1969 http://www.ncbi.nlm.nih.gov/pubmed/22642061 109(17-18):898 https://connects.catalyst.harvard.edu/Profiles/profile/171304696