Authors: R F Casper; H J Erskine; D T Armstrong; S E Brown; S A Daniel; G R Graves; A A Yuzpe Journal: Fertil Steril Date: 1988-04 Impact factor: 7.329
Authors: R J Levine; R M Mathew; C B Chenault; M H Brown; M E Hurtt; K S Bentley; K L Mohr; P K Working Journal: N Engl J Med Date: 1990-07-05 Impact factor: 91.245