1. Cataract extraction with the iris retractor Author(s): Valk, Francis, 1845- author Publication: New York : D. Appleton and Company, [1893?] Subject(s): Cataract Extraction -- methodsIris -- surgery
2. Strabismus, or crossed eyes: how shall we treat them? Author(s): Valk, Francis, 1845- author Publication: New York : D. Appleton and Company, [1894] Subject(s): Strabismus -- therapyStrabismus -- surgeryEyeglasses
3. An operation for shortening the ocular muscles in asthenopia, etc Author(s): Valk, Francis, 1845- author Publication: New York : D. Appleton and Company, [1896] Subject(s): Asthenopia -- surgeryOculomotor Muscles -- surgery