A. P. Tamala, F. Nazarullail, S. F. Fitroh, A. Fitriyono, and E. O. Oktavianingsih, “Enhancing Gross Motor Skills through Competition-Based Obstacle Play: An Effectiveness Study at TK Khadijah Surabaya”, NAKKANAK.J.Child.Research, vol. 2, no. 4, pp. 145–157, Nov. 2025.