Schellenberg GD, Bird TD, Wijsman EM, Moore DK, Boehnke M, Bryant EM, Lampe TH, Nochlin D, Sumi SM, Deeb SS. Absence of linkage of chromosome 21q21 markers to familial Alzheimer's disease. Science. 1988 Sep 16;241(4872):1507-10. PubMed Abstract