P E N Y U L U H A N T E N T A N G P E M A N F A A T A N D A U N S I R I H M E R A H T E R H A D A P P E N Y E M B U H A N L U K A P E R I N E U M P A D A SAAT N I F A S - Siagian, Nurul Aini (INSTITUT KESEHATAN DELI HUSADA, 2021)