张怡筠. (2007). 工作其实很简单: Manage your work easily. 河北教育出版社.
Chicago Style (17th ed.) Citation张怡筠. 工作其实很简单: Manage Your Work Easily. 河北教育出版社, 2007.
MLA (8th ed.) Citation张怡筠. 工作其实很简单: Manage Your Work Easily. 河北教育出版社, 2007.
Advarsel: Disse citationer er muligvist ikke 100% nøjagtige.