https://blog.international-lan.com/how-do-bulgarian-people-learn-english-%e4%bf%9d%e5%8a%a0%e5%88%a9%e4%ba%9a%e4%ba%ba%e5%a6%82%e4%bd%95%e5%ad%a6%e4%b9%a0%e8%8b%b1%e8%af%ad/
How do Bulgarian People Learn English 保加利亚人如何学习英语