Integrated ultrasound-mechanical stirrer technique for extraction of total alkaloid content from Annona muricata - Hau Lee, Chia; Hun Lee, Ting; Ying Ong, Pei; Luing Wong, Syie; Hamdan, Norfadilah; Elgharbawy, Amal A.M.; Azmi, Nurul Alia (Elsevier Ltd., 2021)