TY - JOUR T1 - A Preliminary Note on Branched $ \alpha $-Ray Tracks JF - Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character (1905-1934) VL - 99 IS - 700 SP - 432 EP - 435 PY - 1921/08/02/ UR - http://dx.doi.org/10.1098/rspa.1921.0056 M3 - doi:10.1098/rspa.1921.0056 AU - Shimizu, T. ER -