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), 1065-1077. https://doi.org/10.17762/turcomat.v12i11.5997