1. Erna, M. (2015). Pembuatan dan Penentuan Range pH Kertas Lakmus Sebagai Indikator Asam Basa dari Bahan Alam Sebagai Media Pembelajaran Kimia. 2015. http://repository-universitas-riau/
2. Nuryanti, S., Matsjeh, S., Anwar, C., & Raharjo, T. J. (2010). Indikator Titrasi Asam-Basa dari Ekstrak Bunga Sepatu (Hibiscus rosa sinensis L) Indicator of Acid-Base Titration from the Extract of Hibiscus rosa sinensis L Flower. Jurnal Agritech, 30(3), 178–183.
3. Nuryanti, S., Pursitasari, I. D., & Ratman, R. (2013). Isolation of Anthocyanidin from Wora-Wari Flowers (Hibiscus rosa sinensis L.) and Its Application as Indicators of Acid-base. Jurnal Agritech, 33(03), 320–323.
4. Nuryanti, S., Puspitasari, D. J., & Supriadi, S. (2019). Rosella (Hibiscus sabdariffa) Flowers as Alternative Indicators of Blue and Red Litmus. Oriental Journal of Chemistry, 35(1), 476–480. https://doi.org/10.13005/ojc/350163
5. Nuryanti, S., Sabirin, M., Anwar, C., & Raharjo, T. J. (2012). Isolation anthocyanin from roselle petals (Hibiscus sabdariffa L) and the effect of light on the stability. Indonesian Journal of Chemistry, 12(2), 167–171. https://doi.org/10.22146/ijc.21358