@article{10_37236_1637,
     author = {E. J. Janse van Rensburg and A. Rechnitzer},
     title = {Exchange symmetries in {Motzkin} path and bargraph models of copolymer adsorption},
     journal = {The electronic journal of combinatorics},
     year = {2002},
     volume = {9},
     doi = {10.37236/1637},
     zbl = {1025.05002},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1637/}
}