Works about Pseudo-Dionysius

Catholic Encyclopedia, Volume 5: Diocese-Fathers of Mercy -- from Herbermann, Charles George (1840-1916)
Pseudo-Dionysius -- from The New Schaff-Herzog Encyclopedia of Religious Knowledge
Dictionary of Christian Biography and Literature to the End of the Sixth Century -- from Wace, Henry (1836-1924)
Dionysius, the Pseudo-Areopagite (b. c. 500) -- from Wikipedia Article