Hsu, J. P., & Hsu, L. (2013). Space-time symmetry and quantum Yang-Mills gravity: How space-time translational gauge symmetry enables the unification of gravity with other forces. World Scientific.

Hsu, J. P., and Leon Hsu. Space-time Symmetry and Quantum Yang-Mills Gravity: How Space-time Translational Gauge Symmetry Enables the Unification of Gravity with Other Forces. Singapore: World Scientific, 2013.

Hsu, J. P., and Leon Hsu. Space-time Symmetry and Quantum Yang-Mills Gravity: How Space-time Translational Gauge Symmetry Enables the Unification of Gravity with Other Forces. World Scientific, 2013.