|Other Retailer||Price Checked Time||Their Price in AUD||Our Price|
|Amazon UK||4 days ago||40.19||$23.55||You save $16.64|
|Amazon US||20 days ago||27.01||$23.55||You save $3.46|
About the Authors Frans Plooij, Ph.D., and Xaviera Plas-Plooij are a father-daughter team. Dr. Frans has researched parent-baby interaction for more than 35 years. Xaviera is a Wonder Weeks expert and mother of three. Their child development books, available in 16 languages, have sold more than two million copies worldwide.