Weak e+e− lines from internal pair conversion observed in collisions of 238U with heavy nuclei - Heinz, S.; Berdermann, E.; Heine, F.; Joeres, O.; Kienle, P.; Koenig, I.; Koenig, W.; Kozhuharov, C.; Leinberger, U.; Rhein, M.; Schröter, A.; Tsertos, H. (Springer, 1998)
http://dx.doi.org/10.1007/s100500050028
Keywords: U