http://www.loc.gov/catdir/enhancements/fy1010/2010021887-b.html
http://www.loc.gov/catdir/enhancements/fy1010/2010021887-d.html
http://www.loc.gov/catdir/enhancements/fy1010/2010021887-t.html
http://assets.cambridge.org/97805217/68535/cover/9780521768535.jpg