Prepare Yourself for the Chinese Language Proficiency Exam (HSK). Elementary Chinese Language Difficulty Levels. Volume I: HSK Levels 1 and 2
Language Proficiency Testing for Chinese as a Foreign Language: An Argument-Based Approach for Validating the Hanyu Shuiping Kaoshi (HSK)
Prepare Yourself for the Chinese Language Proficiency Exam (HSK) : Advanced Chinese Language Difficulty Levels. Volume III, HSK Levels 5 and 6