title: Comment on "menstrual disorders in adolescent school girls in Enugu, Nigeria" by Nwankwo et al: does adolescent dysmenorrhea ameliorate after age 20?
authors: Takashi
authors: T
authors: Watanabe
authors: Shigeki
authors: S
authors: Matsubara
authors: Kyoko
authors: K
authors: Asada
authors: Mitsuaki
authors: M
authors: Suzuki
authors: Yukako
authors: Y
authors: Fujinaga