Shimizu Norihiro. Generalization of 'The Problem on Sum of Angles:Consideration from the Viewpoint of Inversion. 2015. 21. 2. 13-27
Shimizu Norihiro. A Framework for Analyzing Informal Representation in Mathematics Class. 2015. 21. 2. 89-102
Shimizu Norihiro. Considering Euler's Fromula(Tan-1(1/2)+Tan-1(1/3)=π/4) from a Geometrical View Point:Various Solutions of Euler's Formula and Viewing Related Formulae from Geometrical Point of View. 2014. 20. 1. 59-71