@article{Gielerak:2009,
author
=
"R.Gielerak and L.Jakóbczyk and R.Olkiewicz",
title
=
"Stochastically positive structures on Weyl algebras : The case of quasi-free states",
journal
=
"Journal of Mathematical Physics",
volume
=
"Vol. 39",
number
=
"no 12",
pages
=
"6291--6327",
year
=
"1998",
}