APA Format
Barbara Purba;
. (1988). Foreword
/
. Jakarta : PPITK
MLA Format
Barbara Purba;
. Foreword
/
. Jakarta : PPITK, 1988
Chicago Format
Barbara Purba;
. Foreword
/
. Jakarta : PPITK, 1988
Australian/Harvard Format
Barbara Purba;
. 1988. Foreword
/
. PPITK Jakarta