Gaya APA
Harefa, A. (2001).
Mutiara pembelajar: Andreas Harefa's values on becoming a learner. .
Yogyakarta:
Yogyakarta Gloria Cyber Ministries.
Gaya MLA
Harefa, Andrias.
"Mutiara pembelajar: Andreas Harefa's values on becoming a learner. ".
Yogyakarta:
Yogyakarta Gloria Cyber Ministries,
2001.
Buku.