Yu, Xue Gang; Yu, Xue Qian Hyperbolic complex functions and the theory of relativity. (Chinese) Zbl 0900.51005 Acta Math. Sci. (Chin. Ed.) 15, No. 4, 435-441 (1995). MSC: 51P05 83A05 PDFBibTeX XMLCite \textit{X. G. Yu} and \textit{X. Q. Yu}, Acta Math. Sci. (Chin. Ed.) 15, No. 4, 435--441 (1995; Zbl 0900.51005)
Wei, Hong Zeng; Wang, Yan Enumeration theorems for finite singular unitary geometries and the construction of PBIB designs. (Chinese) Zbl 0900.51002 Acta Math. Sci. (Chin. Ed.) 15, No. 2, 228-240 (1995). MSC: 51E05 05B05 05B25 PDFBibTeX XMLCite \textit{H. Z. Wei} and \textit{Y. Wang}, Acta Math. Sci. (Chin. Ed.) 15, No. 2, 228--240 (1995; Zbl 0900.51002)