Analyzing 7th graders' Difficulties in Solving Speed-related Word Problems(J.Basis of Science,SNU,2006)
A Case Study on the Behavioral Charateristics of the Middle School-Gifted Students Solving the Open-Ended Mathematical Problems(J.Basis of Science,SNU,2007)
RME자료를 활용한 교수-학습 사례연구-7단계 문자와 식 영역으로-(대한수학교육학회.,2008)
Coincidence Theorems for Nonlinear Hybrid Contractions, Internat. J. Math. &Math. Sci. Vol. 20 No. 2 (1997) 249-256.
An Interesting Property of Probabilistic 2-metric Spaces, Math. Japonica 46, No. 3 (1997), 393-402.
Some Remarks for Improving Fixed Point Theorems for More Than Two Maps, Indian J. Pure and Appl. Math. 28 (1997) 1177-1196.
Fixed point theorems through a rational ex-pression, (1998) 과학과 교육
Some fixed point theorems for expansion mappings in Menger space, Far East Jour. of Math. Sci. Special Vol. (1999), Part I (Geometry and Topology), 55-68
Some fixed point theorems under weak conditions, JP Journal of Geometry and Topology 5(1) (2005), 83-96.
Maps for which F(T)=F(T^n)(with B.E. Rhoades), Fixed point theory and Applications 6 (2005), 87-131.
More Maps for which F(T)=F(T^n)(with B.E. Rhoades), DEMONSTRATION MATHEMATICA 40(3) (2007), 671-680.