This is a textbook on nonlinear mathematics. I bought it two years ago, but I've kept it stored away without reading it. There are some minor scratches on the cover, but the inside is clean as it's unused. "Nonlinear Mathematics (New Mathematics Series)" Hisaya Masuda Price: ¥3000 #HisayaMasuda #Hisaya_Masuda #book #nature/mathematics Differential Equations, Ordinary Differential Equations, Partial Differential Equations, Functional Analysis, Numerical Computation, Probability Theory, Calculus of Variations, Bifurcation Theory