The role of probiotics in improving menstrual health in women with primary dysmenorrhoea: A randomized, double-blind, placebo-controlled trial (the PERIOD study) oleh Izyan Atiqah Zakaria, Nur Aini Mohammed Zain, Chew Kah Teik, Muhammad Azrai Abu, Ani Amelia Zainuddin, Nor Haslinda Abdul Aziz, Nazarudin Safian, Norfilza Mohd Mokhtar, Raja Affendi Raja Ali, Ng Beng Kwang, Nor Azlin Mohamed Ismail, Muhammad Rafiuddin Hamizan, Wira Sorfan Ab Razak, Abdul Ghani Nur Azurah