I only have three paperbacks with covers by Peter Cross, and here they all are:
[CLICK IMAGES TO ENLARGE]
Truth be told, I don’t think any of the above covers is really very good. They deliver an immediate visual punch, and so are well-suited to their purpose, which is to attract attention on crowded bookstore shelves, but they don’t reward close examination for the simple reason that the drawing is weak, and the technique, much too simple. They’re the cover-illustration equivalent of black-light posters and black-velvet paintings, both of which were at the height of their popularity in the 1970s, which is when those editions of John Boyd’s novels were published.