- a recording of the BBC radio programme "Falling Up" from December 2004, featuring contributions from Prof. John Allen of Greenglow, as well as Nick Cook, Paul Horwood, John Searl and Martin Tajmar. Apologies for the poor quality, but storage space was at a premium back then...
- the 1952 Project Winterhaven proposal by Thomas Townsend Brown.
- the 1981 paper "Antigravity with Present Technology" by F. E. Alzofon.
- the 1969 book "New Horizons in Electric, Magnetic and Gravitational Field Theory" by W. J. Hooper.
- the 1978 revision of the book "The Sea of Energy" by T. Henry Moray.