APA (7th ed.) Citation

Helly Pradibyo, H. P. (1970). Tantangan Nasional. Leknas.

Chicago Style (17th ed.) Citation

Helly Pradibyo, Herman Pratikto. Tantangan Nasional. Leknas, 1970.

MLA (8th ed.) Citation

Helly Pradibyo, Herman Pratikto. Tantangan Nasional. Leknas, 1970.

Warning: These citations may not always be 100% accurate.