Coauthor with J. L. Gross, Topological Graph Theory (Wiley, 1987; Dover paperback 2001)
Coauthor (with many others) of texts of the NSF-supported Harvard Calculus Consortium: Calculus (Wiley, 1994; 5th edition 2009) and Multivariable Calculus (Wiley, 1996; 5th edition 2009)
Coeditor with J.L. Gross, L. Beinecke, R. Wilson, Topics in Topological Graph Theory, Cambridge University Press, 2009; includes chapters "Symmetric Maps" (with J, Siran), "The Genus of a Group," and "A Programmatic Overview" (with J.L. Gross)
Fifty papers in 21 journals including Transactions of the American Mathematical Society, Annals of Mathematics, Oxford Quarterly Journal, Journal of Combinatorial Theory, Topology, Journal of the European Mathematical Society.
Some recent examples:
With R. B. Richter, J Siran, R. Jajcay, M Watkins, "Cayley maps," J. Combinatorial Th (B) 95 (2005), 189-245
With M Conder, R. Jajcay, "Regular Cayley maps for abelian groups", J. Algebraic Combinatorics 25 (2007), 259-283
With M. Conder, J Siran, "The genera, reflexibility, and simplicity of regular maps", J. European Math. Soc 12 (2010), 343-364
"Distinguishing maps," Electronic J. Comb. 18 (2011), P50
With M. Conder, "The spectrum of the symmetric genus," Ars Mathematica Contemporanea, 4 (2011), 271-289
With J. L. Gross, "All celtic knots are alternating," Discrete and Computational Geom. 46 (2011), 83-96
With S. Smith and M Watkins, "Distinguishability of infinite graphs and groups," Electronic J. Comb. 19 (2012), R27
With Marston Conder, "The classification of regular Cayley maps for cyclic groups," Trans. Amer. Math Soc. to appear (28 pages)