1. A First Course in Discrete Mathematics;Anderson,2001
2. The Motzkin family;Barcucci;Pure Math. Appl. Ser. A,1991
3. Catalan, Motzkin, and Riordan numbers;Bernhart;Discrete Math.,1999
4. Enumerative Combinatorics;Charalambides,2002
5. Advanced Combinatorics;Comtet,1974