Found in articles
Graham Thurgood, Randy J. LaPolla (2003). Psychology Press: The Sinón-Tibetan languages Volume 3 of Routledge language family series. ISBN 0-7007-1129-5
Daniel T. (Marzu 1993). «Playing with fire? alpine choughs play with a Tibetan red fox» (PDF). Journal, Bombay Natural History Society 90: páxs. 513–515