^"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^Thompson J, Koumari R, Wagner K, Barnert S, Schleussner C, Schrewe H, Zimmermann W, Muller G, Schempp W, Zaninetta D, et al. (May 1990). "The human pregnancy-specific glycoprotein genes are tightly linked on the long arm of chromosome 19 and are coordinately expressed". Biochem Biophys Res Commun. 167 (2): 848–59. CiteSeerX10.1.1.655.1870. doi:10.1016/0006-291X(90)92103-7. PMID1690992.