Extremal Problems in Graph Theory, Chris Hartman, Ph.D. Thesis, University of Illinois, 1997. ps pdf

 

Subcolorings and the subchromatic number of a graph. John Gimbel and Chris Hartman. Submitted to Discrete Math. pdf

 

Spernerís Lemma, Pouzetís Lemma, The Brouwer Fixed Point Theorem and the Theorem of (the game of) Hex. A talk Iíve given more than once that I really need to write up into a paper. In pdf.

 

There are others, I just havenít put them here yet.