TY - JOUR AU - GouvĂȘa, Fernando Q. AU - Mazur, Barry TI - On the characteristic power series of the U operator JO - Annales de l'Institut Fourier PY - 1993 SP - 301 EP - 312 VL - 43 IS - 2 PB - Institut Fourier PP - Grenoble UR - http://www.numdam.org/articles/10.5802/aif.1332/ DO - 10.5802/aif.1332 LA - en ID - AIF_1993__43_2_301_0 ER -