1.
Girsang LC, Fachrial E, Lister INE. Effectiveness Test of Robusta Coffee (Coffea cenephora) Extract from North Sumatra in Collagen and Hydration Skin Level of Female Wistar Rattus norvegicus. ASRJETS-Journal. 2020;65(1):108-115. Accessed October 4, 2025. https://asrjetsjournal.org/American_Scientific_Journal/article/view/5661