Dhage, D. C. “?MIXED MONO TONICITY THEOREMS FOR A SYSTEM OF ABSTRACT MEASURE DELAY INTEGRO-DIFFERENTIAL EQUATIONS”. Biological Sciences - PJSIR, vol. 42, no. 5, Oct. 1999, pp. 236-41, https://v2.pjsir.org/index.php/biological-sciences/article/view/2169.