Trundle, K.C. Teaching science during the early childhood years. National Geographic Learning/Cengage. Retrieved from https://ngl.cengage.com/assets/downloads/ngsci_pro0000000028/am_trundle_teach_sci_early_child_scl22-0429a.pdf
Trundle, K.C. Teaching science during the early childhood years. National Geographic Learning/Cengage. Retrieved from https://ngl.cengage.com/assets/downloads/ngsci_pro0000000028/am_trundle_teach_sci_early_child_scl22-0429a.pdf