Demonstrations of various teaching methods can be found at https://www.youtube.com/watch?v=Pz0TPDUz3FU

A chapter about the history of teaching speaking and listening: http://thesis.univ-biskra.dz/1696/5/Chapter%201.pdf

A short list of ideas for teaching speaking to children: https://www.scholastic.com/teachers/articles/teaching-content/teaching-ell-speaking-strategies/

Ten strategies to get language learners speaking: https://www.fluentu.com/blog/educator-english/speaking-strategies-for-esl-students/