E-Learning resources
This digital teaching material is based on <Indonesian Travel Frog CALLed (Petualangan Katak di Indonesia) > by Rau, D. Victoria, Priska Lydia S. Pulungan, Apriliana Lase, Ganda Christian Panggabean, and Afrinda Samosir (2019).
These e-books (Ann Hui-Huan Chang, 2020) for Android mobile operating system were made with SIL Reading App Builder (https://software.sil.org/readingappbuilder/).