Analysis of observations of earliest visibility of the lunar crescent Alrefay, T. ; Alsaab, S. ; Alshehri, F. ; Alghamdi, A. ; Hadadi, A. ; Alotaibi, M. ; Almutari, K. ; Mubarki, Y. Abstract Publication: The Observatory Pub Date: December 2018 Bibcode: 2018Obs...138..267A