Separating points by spheres. - William Simons; George Trapp (Discret. Math., 1974)

Another way to solve nine-tails. - Franz A. Delahan; William F. Klostermeyer; George Trapp (ACM SIGCSE Bull., 1995)

Using Complex Variables to Estimate Derivatives of Real Functions. - William Squire; George Trapp (SIAM Rev., 1998)

The density of ones in Pascal's rhombus. - John L. Goldwasser; William Klostermeyer; Michael E. Mays; George Trapp (Discret. Math., 1999)