L. Ernawati, R. A. Wahyuono, A. Halim, N. Widiastuti, A. Sabrina, and K. Handayani, “Silk Fibroin/Soursop Seed Bio-Adsorbent for Crystal Violet and Copper Metal Ion Removal ”, J. Eng. Technol. Sci., vol. 54, no. 5, p. 220514, Sep. 2022.