Yuan, Xuehai; Shi, Yiying; Zhang, Cheng Category of concave functions. (Chinese. English summary) Zbl 1057.18002 J. Liaoning Norm. Univ., Nat. Sci. 26, No. 3, 225-227 (2003). MSC: 18B99 90C26 PDFBibTeX XMLCite \textit{X. Yuan} et al., J. Liaoning Norm. Univ., Nat. Sci. 26, No. 3, 225--227 (2003; Zbl 1057.18002)
Yuan, Xuehai; Du, Chunjuan Fuzzy objects and fuzzy category in a topos. (Chinese. English summary) Zbl 0982.18004 J. Liaoning Norm. Univ., Nat. Sci. 24, No. 2, 113-117 (2001). MSC: 18B25 PDFBibTeX XMLCite \textit{X. Yuan} and \textit{C. Du}, J. Liaoning Norm. Univ., Nat. Sci. 24, No. 2, 113--117 (2001; Zbl 0982.18004)
Yuan, Xuehai The definitions of middle object and weak topos. (Chinese. English summary) Zbl 0959.18002 J. Liaoning Norm. Univ., Nat. Sci. 23, No. 3, 225-229 (2000). MSC: 18B25 54A40 54B30 PDFBibTeX XMLCite \textit{X. Yuan}, J. Liaoning Norm. Univ., Nat. Sci. 23, No. 3, 225--229 (2000; Zbl 0959.18002)