'Fighting Techniques of the Oriental World A.D. 1200 to 1860: Equipment, combat skills and tactics' by Michael E. Haskew, Christer Jorgensen, Chris McNab, Eric Niderost, Rob S. Rice. The sections on Chinese warfare is sparse in this volume. It's mostly about the Mongols, Japanese and others. The Chinese? Defeated city-dwellers!
'Medieval Chinese Warfare 300-900' by David A. Graff.