Peters and Barry Guitar, in their textbook Stuttering — An Integrated Approach to Its Nature and Treatment, current views about the causes “will be outdated as more studies fill in the huge gaps in our knowledge about stuttering. ”
Petersi ja Barry Guitari õpiku ” Kogelemine — selle olemuse täiendav uurimine ja ravimine ” (” Stuttering — An Integrated Approach to Its Nature and Treatment ”) järgi muutuvad praegused arusaamad kogelemise põhjustest ” iganenuks, kui uuemad uuringud täidavad suured lüngad sellest arusaamisel ”.