WJ
William H. Keith Jr.
William H. Keith is an American author mainly contributing to military science fiction and military fiction and related game design, who writes also under several pen names, such as Ian Douglas, Robert Cain and H. Jay Riker. His newer original works are written under the name of Ian Douglas.
Excerpt from Wikipedia, available under CC BY-SA 4.0.
Books

Decision at Thunder Rift
1992
ISBN 9780451451842
Bolo Strike
2002
ISBN 9780743435666