1. Biological Foundations of Language;Lenneberg,1967
2. The Age Factor in Second Language Acquisition;Singleton,1995
3. The Psychology of the Language Learner: Individual Differences in Second Language Acquisition;Dörnyei,2005
4. Individual Differences in Second Language Proficiency: Working Memory as Language Aptitude;Miyake,1998
5. Changes in executive control across the life span: Examination of task-switching performance.