PhD thesis by Hawking's student Fay Dowker, titled: Space-time wormholes
1990
1990
1926
1988
2011
1986
2007
2006
1982
1999
2006
1998
1988
1986
2004
1982
1999
1973
2010
1995
2010
1997
2001
1993
1982
1984
1985
1995
1975
1996
1980-1984
2016
1976-1977
1928
1936
1982
1968
1999
circa 1987
1996
1969
1985
1964
2007
1983
1982
2009
1976
1970
1970
2000