Dave Pether: Woman on the Beach ( Unknown book cover )

This original painting was likely produced for a book cover, though the title is presently unknown: it's similar in style to paintings Pether created for novels by Michener, as well as romances - I am hoping that someone will recognize the painting and we'll solve the mystery! I will say this is a very fine painting, and beautifully rendered in gouache and acrylic and possibly tempura, on illustration board 12.75" x 18" and I have a label affixed to the back attesting to authenticity.