Hou, S., Chappellaz, Jouzel, J., J., Chu, P., Masson-Delmotte, V., Qin, D., Kang, S., Raynaud, R., Mayewski, P.A. and Lipenkov, V.Y., 2007, Summer temperatures for the past two millennia using air content along two Himalayan ice cores, Climate of the Past 3, 89-95.