http://www.pal.ua.edu/development/nurturing_children.php
http://www.cdc.gov/ncbddd/childdevelopment/index.html
http://www.nccp.org/publications/pub_882.html
http://onlinelibrary.wiley.com/book/10.1002/9780470757703
http://www.questia.com/PM.qst?a=o&d=28160055#
http://www.cdc.gov/ncbddd/childdevelopment/index.html
http://www.nccp.org/publications/pub_882.html
http://onlinelibrary.wiley.com/book/10.1002/9780470757703
http://www.questia.com/PM.qst?a=o&d=28160055#