For once, YouTube pushed something at me that's genuinely worthwhile:
The Master Photographer You've Never Heard Of
There's also a webpage for Yankang on the Vu Agency website:
Yang Yankang
To me, these are really wonderful photos. The compositions and timing are superb. The series on buddhism in Tibet, in particular, is breathtakingly beautiful.
A comment under the YouTube video states that Yankang is actually well known inside China, but not so much outside. I've searched Photrio, and as far as I can tell, there has been no previous mention of him here.