APA
PURWOKO H., I.M Hendrarti & Rio Rinaldo. (2006). Stepping Stone English For Junior High School Grade 2. Jakarta: Erlangga.
Chicago
PURWOKO Herudjati, I.M Hendrarti and Rio Rinaldo. 2006. Stepping Stone English For Junior High School Grade 2. Jakarta: Erlangga.
Harvard
PURWOKO H., I.M Hendrarti and Rio Rinaldo. (2006). Stepping Stone English For Junior High School Grade 2. Jakarta: Erlangga.
MLA
PURWOKO Herudjati, I.M Hendrarti and Rio Rinaldo. Stepping Stone English For Junior High School Grade 2. Jakarta: Erlangga. 2006.