Where is their methodology described in a journal article? 1997 is 7 years ago, plenty of time for them to have written a short paper. Surely you're not going to rely only on a second-hand report in a newspaper when China has several geophysical journals. Also, technically, they missed in predicting a 7 to 7.5, which did not occur, and the later 6's were outside their 6 day window.

But still the performance as described is impressive. Unfortunately, most prediction work in China, such as the LURR's pattern, has not proven reproducible.

John