Autor: Roslyn Ann Duffy

M.A. Cheryl Erwin & Roslyn Ann Duffy: Positive Discipline: The First Three Years

M.A. Cheryl Erwin & Roslyn Ann Duffy: Positive Discipline for Preschoolers

Roslyn Ann Duffy & Linda Escobar: Positive Discipline: A Teacher’s A-Z Guide

M.A. Cheryl Erwin & Roslyn Ann Duffy: Positive Discipline for Preschoolers, Revised 4th Edition

M.A. Cheryl Erwin & Roslyn Ann Duffy: Positive Discipline: The First Three Years, Revised and Updated Edition