张凯元著. (2017). 慢销售，卖得快. 花山文艺出版社.
Lua i Stíl Chicago (17ú heag.)张凯元著. 慢销售，卖得快. 花山文艺出版社, 2017.
Lua MLA (8ú heag.)张凯元著. 慢销售，卖得快. 花山文艺出版社, 2017.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
Lua APA (7ú heag.)