Situmorang, A. S.; Sinaga, J. A. B.; Rintaningrum, R.; Siagian, R. C. Non-Linear Force Dynamics in Black Hole Accretion Disks Using Logarithmic and Trigonometric Approximations . jppipa, pendidikan ipa, fisika, biologi, kimia 2025, 11, 988-1000.