Influence of physical, biological cohesions, oil and grease on the incipient sediment motion in sewerage pipes oleh Wan Hanna Melini Wan Mohtar, Zohreh Sheikh Khozani, Zalina Mohd Ali, Noor Diyana Ramlee, Wan Rosmanira Ismail, Babak Lashkar Arai Mohammadreh, Zaher Mundher Yaseen