Ryan, P. J. (1986). Euclidean and non-euclidean geometry: An analytic approach. Univ. pr.
Chicago-čujuhus (17. p.)Ryan, Patrick J. Euclidean and Non-euclidean Geometry: An Analytic Approach. Cambridge: Univ. pr, 1986.
MLA-čujuhus (9. p.)Ryan, Patrick J. Euclidean and Non-euclidean Geometry: An Analytic Approach. Univ. pr, 1986.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.