The electronic-preprint service, now known as the "arXiv" (the X stands in for the Greek letter "chi"), is created in 1991 at Los Alamos National Laboratory by Paul Ginsparg. In 2001, arXiv operations are transferred to Cornell University. The arXiv and the Physical Review are linked: e-prints that are published in a journal can have a journal reference in the arXiv entry, and the APS supports citations to the arXiv and has a mirror site http://aps.arXiv.org/.