Motif Programming in the X Window System Environment, William A. Parrette, McGraw-Hill, 1993.
Motif Programming: The Essentials--and More, Marshall Brain, Digital Press, 1992.
Motif Programming Manual, Dan Heller, O'Reilly & Associates, 1992.
Motif Reference Manual, Paula Ferguson, O'Reilly & Associates, 1992.
The X Window System Programming and Applications with Xt, OSF/Motif Edition, Douglas Young, Prentice Hall, 1990.