This guy's method is a very solid approach to learning languages especially for Romance and Germanic languages, even if his claimed results (C1 in 5 months) are

This guy's method is a very solid approach to learning languages especially for Romance and Germanic languages, even if his claimed results (C1 in 5 months) are hard to believe for ordinary people. Two other resources which are inline with his approach are the Assimil series, which is highly regarded by non-academic linguists (and some practical academics), and the LingQ words-in-context language learning website.