@article{Piskorski:2009,
author
=
"J.Piskorski",
title
=
"The operator form of the effective potential governing the time evolution in n-dimensional subspace of states",
journal
=
"Acta Physica Polonica, Series B.",
volume
=
"Vol. 31",
number
=
"no 4",
pages
=
"773--787",
year
=
"2000",
}