Here are the links I provided
1. Multilingual Children’s Speech website (lots of free resources): https://www.csu.edu.au/research/multilingual-speech
2. Speech acquisition posters: https://www.csu.edu.au/research/multilingual-speech/speech-acquisition
3. Speech acquisition studies: https://www.csu.edu.au/research/multilingual-speech/speech-acq-studies
4. Intelligibility in Context Scale in 60+ languages: https://www.csu.edu.au/research/multilingual-speech/ics
5. OPEN ACCESS - McLeod and Crowe (2018) Children's Consonant Acquisition in 27 Languages: A Cross-Linguistic Review https://pubs.asha.org/doi/10.1044/2018_AJSLP-17-0100
6. OPEN ACCESS - Crowe and McLeod (2020) Children's English Consonant Acquisition in the United States: A Review https://pubs.asha.org/doi/10.1044/2020_AJSLP-19-00168
7. Waiting for Speech Pathology https://wnswlhd.health.nsw.gov.au/our-services/speech-pathology/multilingual-resources/
8. New paper - Wren, Y., Pagnamenta, E., Orchard, F., Peters, T. J., Emond, A., Northstone, K., Miller, L. L., & Roulstone, S. (2023). Social, emotional and behavioural difficulties associated with persistent speech disorder in children: A prospective population study. JCPP Advances, e12126. https://doi.org/10.1002/jcv2.12126