Free Download The Golden Section… By Hans Walser, Jean Pedersen, Peter Hilton Publisher The Mathematical Association of America 2001 ISBN 0883855348,9780883855348..

Free Download Lobachevski illuminated… By Seth Braver Publisher The Mathematical Association of America 2011 ISBN 0883855739,978-0-88385-573-7,978-0-88385-979-7..