"Piotr Gibas is an associate professor for Chinese language and literature at the College of Charleston in South Carolina. He holds a PhD from UC Berkeley and is fluent in Chinese (Mandarin), English, German, Russian, Spanish, and several other languages. Werner Skalla is a co-founder of the online language school Skapago. He is fluent in five languages. In 2014 he published his first textbook ""The Mystery of Nils"" for Norwegian. Since then he has published ""Jens & Jakob"" (for German) and ""Alfred the Ghost"" (for Swedish)."