Thomas Brunn Bernhard Möller Martin Russling Layered Graph Traversals and Hamiltonian Path Problems - An Algebraic Approach. 96-121 http://link.springer.de/link/service/series/0558/bibs/1422/14220096.htm 1998 conf/mpc/1998 MPC db/conf/mpc/mpc98.html#BrunnMR98