Budiastra IW, Jannah FR. Non Destructive Determination of Soursop Firmness and Sweetness With Ultrasonic Method. JTEP-L [Internet]. 2022 Jun. 30 [cited 2026 Jun. 28];11(2):253-65. Available from: https://jtep.fp.unila.ac.id/index.php/JTP/article/view/5865