In Graphing Calculator and Computer Graphing Laboratory Manual, Wickes wrote Section 9, "Working with the HP 48 Scientific Calculator" (25 pages, with a five-item Bibliography):
9.1 HP 48 Fundamentals (7 pages)
9.2 Graphing Essentials
9.3 Working in Interactive Plot Mode
9.4 Polar Graphing
9.5 Parametric Graphing
It's interesting to see Wickes do all this in such a small space, of course.
ISBN 0-201-56852-7
Addison-Wesley, 1992; reprinted with corrections, 1993
Overall authors Franklin Demana, Bert K. Waits, Chuck Vonder Embse, and Gregory D. Foley
(A supplement, published in 1994, has a 15-page section on "Graphing with the HP 48G," but Wickes seems to have had nothing to do with that.)