Anthonio, Y. O., K. Rauf, A. A. Abdurasid, and O. R. Aderele. “Multivariate Opial-Type Inequalities on Time Scales”. Earthline Journal of Mathematical Sciences, Vol. 12, no. 1, Jan. 2023, pp. 13-26, doi:10.34198/ejms.12123.1326.