8,836 Nurul Jannah Abdullah 2020-03-26 https://hort.purdue.edu/newcrop/morton/soursop.html Purdue University. (2017). Soursop. Retrieved from https://hort.purdue.edu/newcrop/morton/soursop.html https://en.wikipedia.org/wiki/Soursop#cite_note-PIER-6 Wikipedia. (2020). Soursop. Retrieved from https://en.wikipedia.org/wiki/Soursop#cite_note-PIER-6