Sponsorship Disclosure

SPEKTRA was published in cooperation of:

• Fisika UNJ
• LPPM UNJ
• HFI Jakarta 
• HFI

Discount 50% of APCs (Article Processing Charges) for HFI member who submitted manuscript and accepted status in 2020. This offer is valid only for active HFI members, please write down the ID number in comments for editor when submitting manuscript.