Here's an interesting video on YouTube addressing Unitarian interpretations of Titus 2:13:
The Failure of Unitarianism: Titus 2:13
See also:
Sharp Redivivus? - A Reexamination of the Granville Sharp Rule by Daniel B. Wallace
Sharp’s Rules and Antitrinitarian Theologies: A Defense of Granville Sharp’s Argument for the Deity of Christ by Robert M. Bowman, Jr. [or Here]
Granville Sharp's Rule Titus 2:13 and 2 Peter 1:1 by James White
