1. Adamopoulou, E., & Moussiades, L. (2020). “Chatbots: History, technology, and applications”. Machine Learning with Applications, 2, 100006.
2. Amazon Alexa, “Learn more about Alexa features, skills, and products.”, https://www.alexa.com, May 2022.
3. Amazon Lex, “Conversational AI and Chatbots – AWS”, https://aws.amazon.com/lex/, May 2022.
4. Anki - powerful, intelligent flashcards https://apps.ankiweb.net/.
5. Forgetting versus savings: The many facets of long-term retention