Motivation to Learn: An Overview
http://www.edpsycinteractive.org/topics/motivation/motivate.html
How Motivation Affects Learning and Behavior
http://www.education.com/reference/article/motivation-affects-learning-behavior/
Motivation in Second Language Learning
http://en.wikipedia.org/wiki/Motivation_in_second-language_learning
Intrinsic vs Extrinsic Motivation
http://userpages.umbc.edu/~koconne1/605TheAdultLearner/ivse.htm
The Language Learner: Motivation Predicts Success
https://coerll.utexas.edu/methods/modules/learners/02/
Motivation to Learn