Acts of Barnabas
Fifth-century work tells of Barnabas's journey to Cyprus and martyrdom at Salamis. From the Ante-Nicene Fathers (American edition), vol. 8. In HTML, with notes, at Christian Classics Ethereal Library.
Catholic Encyclopedia
St. Barnabas, originally called Joseph, missionary, called an Apostle.
James Kiefer's Christian Biographies
St. Barnabas the Apostle. With prayer in traditional and contemporary language.
Patron Saints Index
Profile of St. Barnabas the Apostle. Illustrated.
The Ecole Glossary
Short biography of St. Barnabas, by Karen Rae Keck.