Gaya APA
LEO, S., W, B, R, [. (2013).
A Challenging book to practice teaching in english .
Yogyakarta:
Andi Offset.
Gaya MLA
LEO, Sutanto., W, Benedicta, Rini, [ed.].
"A Challenging book to practice teaching in english".
Yogyakarta:
Andi Offset,
2013.
Buku.