D Smitherman, W McClure, D A O'Neil, L R Young, K Calhoun-Senghor, C S Rappaport, S Pace, N Marzwell, J Spencer, H Wolff, J Grey, L Rowell, D O'Neil & E Stallmer (ed D O'Neil, J C Mankins, I Bekey, T Rogers, E Stallmer & W Piland), February 1999, "General Public Space Travel and Tourism Volume 2 - Workshop Proceedings", NASA/CP-1999-209146..
Also downloadable from http://www.spacefuture.com/archive/general public space travel and tourism volume 2.shtml