@Book{551218045,
author="S{\o}rensen, Per K.
and Hazod, Guntram
and Tshe-ring-rgyal-po",
title="Rulers on the celestial plain",
series="Denkschriften",
year="2007",
address="Wien",
note="Per K. S{\o}rensen and Guntram Hazod in cooperation with Tsering Gyalbo",
language="English"
}