Age and Language Learning
http://www.language-learning-advisor.com/age-and-language-learning.html
What's the Best Age to Learn a New Language?
http://people.howstuffworks.com/best-age-learn-language.htm
Language Learning and Age
http://hrd.apec.org/index.php/Language_Learning_and_Age
The Age Factor in Second Language Acquisition
http://termcoord.eu/2014/02/age-factor-second-language-acquisition/
Age and Second Language Acquisition and Processing: A Selective Overview
http://uts.cc.utexas.edu/~birdsong/birdsong/age2ndlang.pdf
Understanding Ages and Stages