TY - JOUR T1 - Fifth-order AGM-formula for the period of a large-angle pendulum JO - Revista Brasileira de Ensino de FĂ­sica A1 - Big-Alabo, Akuro SN - 1806-1117 UL - 10.1590/1806-9126-RBEF-2023-0014 VL - 45 Y1 - 2023 PB - Brasil ER -