English: theory of 2nd‐order linear ODEs that are eigenvalue equations of the operator 𝑤 ⁻¹ 𝑝 d∕d𝑥+𝑞 )
Japanese: −𝑤 ⁻¹ 𝑝 d∕d𝑥+𝑞 )𝑦 =𝜆𝑦 の型の二階線形微分方程式に関する理論