1. Fostering recursive thinking in combinatorics through the use of manipulatives and computer technology;Abramovich;The Mathematics Educator,1996
2. Graph chasing across the curriculum: Paths, circuits, and applications;Althoen,1991
3. Common errors in counting problems;Annin;Mathematics Teacher,2010
4. Effect of the implicit combinatorial model on combinatorial reasoning in secondary school pupils;Batanero;Educational Studies in Mathematics,1997
5. Combinatorial reasoning and its assessment;Batanero,2005