This page is meant to list books (by author) and web sites (by topic) that students may find helpful or challenging. I'll try to update the page regularly.

• David W. Farmer, Groups And Symmetry, A Guide to Discovering Mathematics,Mathematical World, Vol. 5, American Mathematical Society, 1996. ISBN 1055-9426; v.5
  
  This is the book I'll be following most closely, although I'll be jumping around a little and adding what feels interesting to me. It is constructed as a work book, with Tasks presented to the student at regular (less than a page, usually) intervals. Highly recommended in general, but not really necessary to follow along.

• David W. Farmer and Theodore B. Stanford, Knots and Surfaces, A Guide to Discovering Mathematics,Mathematical World, Vol. 6, American Mathematical Society, 1995. ISBN 0-8218-0451-0.
  
  Another book by Farmer, this time with Stanford. I don't plan on using this a whole lot, but it was useful for some information on knots (and teaching knots) from chapter 3. It seems like another interesting read, but mostly it is on topics we're not covering.

• Alexander H. Frey, Jr. and David Singmaster, Handbook of Cubik Math, Enslow Publishers, Hillside, NJ, 1982. ISBN 0-89490-060-9.
  
  A wonderful book about the cube, from the heyday of its popularity. Based in part on earlier books by Singmaster, this is more than just a solutions guide -- it's full of discussions of groups and subgroups. Highly recommended.

• Branko Grunbaum and G.C. Shephard, Tilings And Patterns, W.H. Freeman, New York, 1987.
  
  A classic book. Perhaps a bit over our heads at times, but still the standard book in the field.

• Magnus J. Wenninger, Polyhedron models, Cambridge University Press, 1971.
  
  A beautiful book on making paper models of polyhedra.

• Prof. W. D. Joyner has a nice page on Rubik's cube-like puzzles. He has also written some nice lecture notes (now a book) that were used in conjunction with Frey and Singmaster for weeks twelve and thirteen.
• The Official Rubik's Site
• A Rubik's cube page from Michael Reid that is a great source for mathematics and the cube

• Mathematics and Knots Exhibition A beautiful exhibition at the University of Wales, Bangor.
• The KnotPlot Site Another beautiful site. This one includes a catalogue of links (and knots) by the number of their minimal crossings. Also it has the computer program KnotPlot, which you may use to draw knots (and knots on the torus).
• Knots on the Web (Peter Suber) This site really provides a better bibliography than I could come up with. It's the place to start surfing, really.
• A page on Unknot Equivalence where I originally found Goeritz's knot. It shows how to see that it is the unknot.
• A Java Knot Simplifier

• Infinite Ink has a nice page on the Continuum Hypothesis.
• There is a short but interesting page on the Continuum Hypothesis from Math World (Wolfram).

• A nice list of groups of small order from the University of South Florida.
• A nice page from Holland defining finite groups and listing up to order 15 (and counting abelian and non-abelian groups up to order 400).

• The Journal of Online Mathematics and its Applications has nice pages on the seven frieze patterns and the seventeen wallpaper patterns.
• Some examples from classes at the University of Georgia: two students (Kelli Nipper and Shannon Umberger) did a project in Symmetry in Architecture with some nice examples of both wallpaper and strip patterns from the real world. Jongsuk Keum has some simple, but nice, examples of the seven types of Strip Pattern Symmetry.
• David Joyce at Clark University has some nice pages on the seventeen wallpaper groups, with a nice discussion of the history of such things.
• Check out QuasiTiler and Kali if you haven't already! (Referenced below as well.)

• Check out RSA Security, Inc, the company spawned by this algorithm. Check out their factoring challenges.
• Pages from a course at Princeton (instructor Ingrid Daubechies) on the number theory behind RSA. See lab 1. This is essentially what we did in class on Tuesday, November 19th.
• Another course (from UMIST) with another explanation of the algorithm. See Worksheet 7.
• The RSA Algorithm Javascript Page
• Subhashis Banerjee has a nice (but brief) introduction to RSA.

• A page on semi-regular tilings of the plane, which we didn't discuss.
• An introduction to tilings from Science U.
• Penrose tilings (also from Science U), the standard example of (beautiful) aperiodic tilings.
• A page on the aperiodic tilings of Melbourne, Australia's Federation Square, which (according to my Melbournian office mate) just opened this past weekend.
• QuasiTiler, a computer program that lets you generate aperiodic tilings. There is an article on quasi-crystals and the golden ratio phi here
• Kali, a drawing program that allows you to specify the symmetry group! Also available is Kali-Jot, which adds a few features for X and Mosaic only.

• Korthals Altes has some nice models for paper polyhedra, with PDF files
• douglas zongker | polyhedra models, a beautiful page with PDF templates
• georgehart.com, another beautiful page with virtual tours of polyhedra and some extremely complicated polyhedra
• emit.org has the basic polyhedra, but nicely done
• Fr. Magnus Wenninger, who wrote the book on building polyhedra, has a nice page with some of his exotic creations
• The Geometry Junkyard has a page on Models of Polyhedra. Mostly good links to various people's creations.
• A collection of polyhedra-related links from SpaceStation42.com