@article{SF_1977__14_186365,
     author = {M.L. Howard},
     title = {Roots of increasing sequences.},
     journal = {Semigroup forum},
     pages = {167--174},
     publisher = {mathdoc},
     volume = {14},
     year = {1977},
     zbl = {0367.20053},
     url = {http://geodesic.mathdoc.fr/item/SF_1977__14_186365/}
}