沃尔克普 & 麦基. (2009). 用电话向所有人销售: Selling to anyone over the phone. 黑龙江科学技术出版社.
Lua i Stíl Chicago (17ú heag.)沃尔克普 agus 麦基. 用电话向所有人销售: Selling to Anyone over the Phone. 黑龙江科学技术出版社, 2009.
Lua MLA (8ú heag.)沃尔克普 agus 麦基. 用电话向所有人销售: Selling to Anyone over the Phone. 黑龙江科学技术出版社, 2009.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.