Para profissionais - Gagueiras Stuttering and Science William H. Perkins, Singular Publishing Group, 1996. Maiores informações. Section I: WHY SCIENCE HAS NOT SOLVED STUTTERINGA Brief History of Scientific Approaches to the Nature of Stuttering Chapter 1. Theory EraTravis Era: Breakdown and Represses-Need TheoriesJohnson Era: Anticipatory-Struggle and Conditioning Theories Chapter 2. Assumption EraConstitutional AssumptionsSpeech-Motor AssumptionsCritique Chapter 3. Scientifi