Gaya APA
Riskiyanto, ., Hidayat, A, N. (2025).
New Insight OSN: Olimpiade Sains Nasional Geografi SMA/MA .
jakarta:
Gramedia.
Gaya MLA
Riskiyanto, ., Hidayat, Arif, Nur.
"New Insight OSN: Olimpiade Sains Nasional Geografi SMA/MA".
jakarta:
Gramedia,
2025.
Text.