Writing Microsoft Windows Help — Two Steps Past the Basics
http://www.stc.org/confproceed/1996/PDFs/PG0260.PDF

Thomas, Morgan O.
STC Proceedings
1996

Abstract:

With planning, an understanding of organizational devices such as expandable tables of contents, secondary help windows, and graphical navigational aids, you can make your help system easier to use, more attractive, and more useful.