THE EFFECT OF WILLIAM’S FLEXION EXERCISE ON THE LEVEL OF BACK PAIN DOWNTOWN ELDERLY IN THE TRESNA SOCIAL INTEGRATED SERVICE UNIT WERDHA BLITAR IN TULUNGAGUNG DISTRICT. INTERNATIONAL SEMINAR, [S. l.], v. 4, p. 23–33, 2022. DOI: 10.36563/proceeding.v4i0.73. Disponível em: https://conference.unita.ac.id/index.php/conference/article/view/73. Acesso em: 29 sep. 2025.