HarperOne Fluent in 3 Months: How Anyone at Any Age Can Learn to Speak Any Language from Anywhere in the World

Fluent in 3 Months: How Anyone at Any Age Can Learn to Speak Any Language from Anywhere in the World

Fluent Forever (Revised Edition): How to Learn Any Language Fast and Never Forget It

Becoming Fluent: How Cognitive Science Can Help Adults Learn a Foreign Language (Mit Press)