@article{Authenticus:P-001-W4W,
title = {{Power Pseudovarieties of Semigroups-i}},
author = {J ALMEIDA},
doi = {10.1007/bf02573209},
journal = {Semigroup Forum},
number = {3},
pages = {357-373},
publisher = {Springer Verlag},
type = {Article},
volume = {33},
year = {1986}
}