Ezenyeaku, C. C.; Ezebialu, I. U.; Umeobika, J. C.; Akabike, J.; Ezenyeaku, C. A.; Ojiyi, C. E.; Okeke, T. C. Assessment of Age at Menarche and Menstrual Pattern Among Secondary School Girls in Awka, Southeast Nigeria. Int J Reprod Contracept Obstet Gynecol 2021, 10, 2192-2197.