ELMeneza, S., I. ElBagoury, E. . . Tawfik, and A. . Tolba. “Study of Neuropeptide Substance P As A Marker of Pain in Newborn Infant”. Open Access Macedonian Journal of Medical Sciences, vol. 9, no. B, Nov. 2021, pp. 1615-20, doi:10.3889/oamjms.2021.7444.