Contains the keyword SUNYATA
Allen B. The Virtual and the Vacant—Emptiness and Knowledge in Chan and Daoism. Journal of Chinese Philosophy. 2010;37(3):457-71. Abstract
PATT-SHAMIR GA. The 'Dual Citizenship' of Emptiness: A Reading of the Bu Zhenkong Lun. Journal of Chinese Philosophy. 2011;38:474-90. Abstract