SIRGHI, N., M. NEAMTU, G. MIRCEA, and D. RAMESCU. “The Deterministic Model With Time Delay for a New Product Diffusion in a Market”. Timisoara Journal of Economics and Business, Vol. 11, no. 1, Feb. 2019, pp. 55-66, http://tjeb.ro/index.php/tjeb/article/view/TJEB-vol11-2018-iss1-art4-SIRGHI.