Can you learn Chinese from a textbook. Here John and Jared break down if they think you can learn solely from a textbook.
https://youcanlearnchinese.mandarincompanion.com/episodes/27-can-you-learn-chinese-from-a-textbook
An earlier episode of You Can Learn Chinese where they talk on the four keys to learning a language
https://youcanlearnchinese.mandarincompanion.com/episodes/13-the-four-keys-to-learning-chinese-you-need-to-know
The original journal entry on the four strands by Paul Nation
https://www.tandfonline.com/doi/abs/10.2167/illt039.0?journalCode=rill20
The Mandarin Blueprint site
https://www.mandarinblueprint.com/resources/pronunciation-mastery/
The reddit announcement I originally read
https://www.reddit.com/r/ChineseLanguage/comments/azphoq/it_only_took_3_years_the_mandarin_blueprint/
And the Mandarin Blueprint YouTube channel
https://www.youtube.com/channel/UCc5ueW8aqO73Q6MevB8L5PA/videos
Finally the original promo video I saw. Check out Luke's Mandarin at 3:06!!!
https://www.youtube.com/watch?v=RTRGOwgHyW0