Mr Woon has recently published two books, 雲南之寶 : 南詔, 大理國等珍藏 The Hidden Treasures of Nanzhao and Dali Kingdoms, with other artifacts from Yunnan, and 神雲佛光 : 南詔, 大理文物 The Divine Treasures of Nanzhao and Dali Kingdoms, that examined Nanzhao-Dali objects in private collection and museums. The following links will guide you to these two publications (Click on book covers for online reading):
The Divine Treasures of Nanzhao and Dali Kingdoms