Sadjidon, and H. Gunawan. “ONSTRUKSI UANG -ORM EBAGAI UASAN ANG IRENTANG LEH UA EKTOR”. imits: ournal of athematics and ts pplications, vol. 4, no. 2, Nov. 2007, p. 45, https://journal.its.ac.id/index.php/limits/article/view/5405.