@article{Bursa:2009,
author
=
"M.Bursa and M.Abramowicz and V.Karas and W.Kluźniak",
title
=
"The upper kilohertz quasi-periodic oscillation : a gravitationally lensed vertical oscillation",
journal
=
"Astrophysical Journal",
volume
=
"Vol. 617",
number
=
"issue 1",
pages
=
"L45--L48",
year
=
"2004",
}