1. M.Visser Lorentzian Wormholes: from Hawking to Einstein (AIP Press 1995).
2. K.S.Thorne Black Holes and Time Warps (W. W. Norton Woodbury 1994). See also K. S. Thorne in General Relativity and Gravitation 1992 edited by R. J. Gleiser C. N. Kozameh and O. M. Moreschi (Institute of Physics Bristol 1993) pp. 259–315.
3. J.R.Gott Time Travel in Einstein's Universe (Houghton Mifflin New York 2001).
4. T.A.Roman Some thoughts on energy conditions and wormholes arXiv: gr‐qc/0409090 to appear in the proceedings of 10th Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity Gravitation and Relativistic Field Theories (MG X MMIII) Rio de Janeiro Brazil 20–26 Jul 2003.
5. T.A.RomanandL.Ford Scientific American January 2000.