Tyrrell, J. e., Tyrrell, J., & Semple, J. (1971). Generalised clifford parallelism. Cambridge University press.
Dyfyniad Arddull ChicagoTyrrell, J.A ed, J.A Tyrrell, and J.G Semple. Generalised Clifford Parallelism. Cambridge: Cambridge University press, 1971.
Dyfyniad MLATyrrell, J.A ed, et al. Generalised Clifford Parallelism. Cambridge University press, 1971.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.