APA (7th ed.) Zitazioa
Early, G. H. (1969). Perceptual training in the curriculum. C. E. Merrill Pub. Co..
Chicago Style (17th ed.) Zitazioa
Early, George H. Perceptual Training in the Curriculum. Columbus, Ohio: C. E. Merrill Pub. Co., 1969.
MLA (9th ed.) Zitazioa
Early, George H. Perceptual Training in the Curriculum. C. E. Merrill Pub. Co., 1969.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.