1. Objektive Sehscharfebestimmung bei Kleinstkindern;Aichmair;Klin. Mbl. Augenheilk.,1976
2. A new picture series for preschool vision testing;Allen;Am. J. Ophthal.,1957
3. Testing visual acuity in preschool children. Norms, variables and a new picture test;Allen;Pediatrics,1957
4. Visual acuity development in human infants up to 6 months of age;Allen,1979
5. Visual acuity of toddlers tested by operant and preferential looking techniques;Birch;Invest. Ophthal. visual Sci., (Suppl.),1980