A periodical is a professional periodical published regularly, which contains a series of articles, research reports or comments on specific topics. Periodicals can be monthly, quarterly, semi-annual or annual and published by academic institutions, professional associations or publishing houses. The magazine covers the latest research and development in this field. A thesis refers to a work that makes an in-depth study of a certain problem and draws a conclusion in academic research. Thesis can be divided into degree thesis (master's thesis, doctoral thesis) and non-degree thesis. Papers need to go through a rigorous review process before they can be published in academic journals.