^Virginia Mullery (9 سبتمبر 2007). "Underground Bookstore A Cultural Celebration". Chicago Tribune. مؤرشف من الأصل في 2017-11-07. اطلع عليه بتاريخ 2010-12-24. While he carries recognized black authors such as James Baldwin and Maya Angelou, at least half of the books in his shop will not be found in major chains, Colbert said. Included are such authors as Marcus Garvey, A. Ralph Epperson and Haki R. Madhubti.
^See: Birth Certificate of Anthony Ralph Epperson - "Archived copy"(PDF). مؤرشف من الأصل في 2014-08-08. اطلع عليه بتاريخ 2014-07-25.{{استشهاد ويب}}: صيانة الاستشهاد: الأرشيف كعنوان (link)
