The Chinese government on Thursday released a circular calling for stricter supervision over children's publications, a move many parents and publishers call "imperative", in a bid to filter obscene and violent content in children's reading. "The children's publications market has been thriving with many quality works that boost healthy development, but problems also exist, such as shoddy quality, improper content and overly high prices," said the document, which was jointly released by five departments including the Ministry of Education.