Tough, A. (1977). Learning without a teacher: A study of tasks and assistance during adult self-teaching projects (Rev. [ed.].). Ontario Institute for Studies in Education.
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)Tough, Allen. Learning Without a Teacher: A Study of Tasks and Assistance During Adult Self-teaching Projects. Rev. [ed.]. Toronto: Ontario Institute for Studies in Education, 1977.
Trích dẫn kiểu MLA (xuất bản lần thứ 8)Tough, Allen. Learning Without a Teacher: A Study of Tasks and Assistance During Adult Self-teaching Projects. Rev. [ed.]. Ontario Institute for Studies in Education, 1977.
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