Internet History Sourcebooks Project
Fordham University: Medieval Sourcebook: Gregory of Nyssa: Life of Macrina
The complete text of Gregory's book on his sister, Macrina. The book was written during the 4th century.
Society of Archbishop Justus
Gregory of Nyssa 9 March 395
A description of Gregory of Nyssa's commentary on Moses.
Other
Orthodox America: St. Gregory of Nyssa
A description of Gregory of Nyssa's writings, life, and theology. Commemorated January 10th, this Saint is remembered fondly with a short biography and quotes from his various writings.
New Advent
Catholic Encyclopedia: St. Gregory of Nyssa
A detailed biography of the Saint, it also provides a good summary of his major writings.