NCCL's "Looking East" weblog, containing inter alia links to several circular letters (encyclicals) of the Roman magisterium (teaching office) of the Bishop-Father (Pope) of the Holy See of Rome in re the Eastern Churches
Orientale Lumen, Apostolic Letter of Pope John Paul II on "The Light of the East", May 2, 1995 (link opens new window to Vatican website)
The Ukrainian Catholic Church
and Eastern Spirituality by Jaroslav Pelikan - paper delivered at a symposium: The Ukrainian Catholic Church 1945-1975, held at La Salle College - Philadelphia, Pennsylvania USA, 19 April 1975
On spiritual Paternity for Christian discipleship, by an hierarch of the East, Metropolitan Kallistos of Diokleia