Gaya APA
Prihartono, J., Natakusumah, R. (1990).
TRS No. 60 The Quality Test of in Country Lippes Loop 1987 .
Jakarta:
BKKBN.
Gaya MLA
Prihartono, Joedo., Natakusumah, Rusdi.
"TRS No. 60 The Quality Test of in Country Lippes Loop 1987".
Jakarta:
BKKBN,
1990.
Text.