[646] On non-linear differential equations of the second order: IV. The general equation $$\ddot y + kf\left( y \right)\dot y + g\left( y \right) = bkp\left( \varphi \right)$$ , φ=$t$+α, φ=$t$+α

[647] Prediction theory and fourier series in several variables. II

[648] Fixed points and circle maps

[649] Analyticity of intersection exponents for planar Brownian motion

[650] Théorie des groupes fuchsiens