“Analysis Of Differences In Share Prices Before And In Covid-19 Pandemic Era(Case Studies In The Sub-Sector Of Telecommunications, Hotel And Tourism, Health, Bumn Finance, And Transportation Listed On The Indonesia Stock Exchange)” (2021) Turkish Journal of Computer and Mathematics Education (TURCOMAT), 12(11), pp. 1065–1077. doi:10.17762/turcomat.v12i11.5997.