1. Ali A, Ali S, Saleem H, Hussain T (2010) Effect of tannic acid and metallic mordants on the dyeing properties of natural dye extracted from Acacia nilotica Bark. Asian Journal of Chemistry 22(9):7065–7069
2. Brady SR (2015) Utilizing and adapting the Delphi method for use in qualitative research. International Journal of Qualitative Methods 14(5):1–6. https://doi.org/10.1177/1609406915621381
3. Capri A (2019) Micro and small businesses in Indonesia’s digital economy: Keys to developing new skills and human capital. Asia Pacific Foundation of Canada, Canada. https://apfcanada-msme.ca/sites/default/files/2019-03/Micro%20and%20Small%20Businesses%20in%20Indonesia%E2%80%99s%20Digital%20Economy.pdf. Accessed 23 Nov 2020
4. Chamorro A, Miranda FJ, Rubio S, Valero V (2012) Innovations and trends in meat consumption: an application of the Delphi method in Spain. Meat Science 92:816–822
5. Christie RM. (2015) Colour Chemistry (2nd ed.). Royal Society of Chemistry, Cambridge. ISBN 9781849733281