Faaz Nassir AL-Saad, N. “Study of Some Virulence Factor and Detection of Sortase Enzymes A and Cov R/S of Streptococcus Agalactiae by PCR”. Al-Qadisiyah Journal of Pure Science, Vol. 23, no. 2, May 2018, pp. 90 -97, doi:10.29350/jops.2018.23.2.740.