Structural geology : an introduction to geometrical techniques / by, Donal M. Ragan. Ragan, Donal M. Geology, Structural. QE601 .R23 1973 551.8 RAS Includes Index. Bibliography: p. 197-201. New York : Wiley, c1973. c1973. 1973 Text ix, 208 p. : http://www.loc.gov/catdir/enhancements/fy0607/73003335-d.html http://www.loc.gov/catdir/enhancements/fy0607/73003335-t.html eng