Mai believes that Nguyen copied dozens of paragraphs in the book ‘Ngon ngu hoc xa hoi – nhung van de co ban’ (Social linguistics – some basic matters) by Nguyen Van Khang when writing his doctoral thesis. The conclusion by the Academy of Social Sciences about an allegedly plagiarized doctoral dissertation that it contained only ‘unprofessional quoting’ has stirred controversy. After inspection, GASS director Pham Van Duc concluded that there was no plagiarism in the work, and that the thesis had significant discoveries, theoretical and practical. However, inspectors said that the author of the thesis, Nguyen, was only ‘unprofessional’ when quoting other scientific research on pages 17 to 24. Duc emphasized that the inspection council, after thoroughly examining the doctoral thesis, found that the author made quotation mistakes, not plagiarism.