张怡筠. (2007). 工作其实很简单: Manage your work easily. 河北教育出版社.
Dyfyniad Arddull Chicago张怡筠. 工作其实很简单: Manage Your Work Easily. 河北教育出版社, 2007.
Dyfyniad MLA张怡筠. 工作其实很简单: Manage Your Work Easily. 河北教育出版社, 2007.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.