I don't know of a book or list of plants that gophers avoid, but several plants are quite well known. Strong smelling plants especially herbs such as the sages (culinary and ornamental), lavender cotton, lavender, and castor oil, yarrows, hellebores, monk's hood, and euphorbias (spurges) are a few more. Contact your local Cooperative Extension office ( yellow or blue pages of the telephone directory). They may have a list that is useful locally. I think your best bet is to continue to plant in containers or line your flower beds with chicken wire to a depth of about 24 inches.