Measurement of β−-decay continuum spectrum of 138La Agnese Giaz, Giulia Gosta, Franco Camera, Stefano Riboldi, Nives Blasi, Angela Bracco, Sergio Brambilla and Benedicte Million EPL, 110 4 (2015) 42002 Published online: 16 June 2015 DOI: 10.1209/0295-5075/110/42002