Indoor air quality level influence sick building syndrome among occupants in educational buildings by Ismail, Syazwan Aizat, Mohamed Kamar, Haslinda, Kamsah, Nazri, Ardani, Mohd. Ibtisham, Che Dom, Nazri, Shafie, Farah Ayuni, Zulkapri, Izwyn, Lim, Kuang Hock