@article{10_4064_cm_22_1_9_11,
     author = {G. Gr\"atzer and J. P{\l}onka and A. Sekanina},
     title = {On the number of polynomials of a universal algebra, {I}},
     journal = {Colloquium Mathematicum},
     pages = {9--11},
     publisher = {mathdoc},
     volume = {22},
     number = {1},
     year = {1970},
     doi = {10.4064/cm-22-1-9-11},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-22-1-9-11/}
}