Astuti RD, Gandana WE, Pujiyanto E, Nurbi RS. Proposed Design Of Toy To Optimize The Brain Development Of Children Aged 3-5 Years Old. Spek Ind [Internet]. 2022Apr.20 [cited 2024Apr.19];20(1):11-8. Available from: https://journal3.uad.ac.id/index.php/spektrum/article/view/14