https://www.stutteringtreatment.org William Parry, SLP, valsalva stuttering therapy (after you learn the basics,look at this for more info about valsalva https://trumpetguild.org/journal/category/31-conquering-valsalva?download=271:conquering-valsalva Tim Mackesey, SLP, Georgia - free, very useful podcast https://www.stuttering-specialist.com