Isnaeni, I., Purwandari, V., Putro, P.A. and Adiwidya, H.M. 2023. Optical Properties of Sodium-doped Carbon Dots Made of Urea and Trisodium Citrate. TIME in Physics. 1, 1 (Feb. 2023), 1–9. DOI:https://doi.org/10.11594/timeinphys.2023.v1i1p1-9.