@article{PORMA_1967__26_3_115029,
     author = {Waterman, Alan G.},
     title = {The free lattice with 3 generators over $N_5$},
     journal = {Portugaliae mathematica},
     pages = {285--288},
     publisher = {mathdoc},
     volume = {26},
     number = {3},
     year = {1967},
     mrnumber = {0265235},
     zbl = {0207.32104},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1967__26_3_115029/}
}