ASAIHL seminar on agribusiness : higher education contribution to development, Medan, Indonesia : proceedings
edited by T. Marzuki Jacob
Universitas Sumatera Utara, 1994
 Buku Referensi
Best, John W.
Research in education
Pearson, 2014
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Best, John W.
Research in education
Prentice Hall of India, 1982
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Best, John W.
Research in education
Prentice-Hall, 1977
 Buku Teks
Hodgson, Naomi
Citizenship for the learning society Europe, subjectivity, and educational research
West Sussex, UK Wiley Blackwell, 2016
 Buku Teks