Text ( visual ) : unmediated Rotation of a rigid body in quantum mechanics / by H. B. G. Casimir. -- Groningen, The Hague : Wolter , 1931. -- vii, 112 p. ; 21 cm. -- (BA02553660) ; https://ci.nii.ac.jp/ncid/BA02553660 Author Heading(s): Casimir, H. B. G. (Hendrik Brugt Gerhard)