The suggestion that an additional factor might exist was made by Dr Paul Owren (1905–1990), a Norwegian physician, during his investigations into the bleeding tendency of a lady called Mary (1914–2002).
Existenci možného dalšího faktoru navrhl norský lékař Paul Owren (1905-1990) během doby, kdy zkoumal krvácivé stavy u své pacientky Mary (1914-2002).