This is from the ASCAP title search--

MY MAMMY Title Code: 430126517) 
                Writers:
   DONALDSON WALTER
   LEWIS SAMUEL M
   YOUNG JOSEPH

                Performers:
BARBERSHOP QUARTET
BARBERSHOP QUARTETS & CHORUS
CANTRELL L
CHEVALIER M
DONALDSON
FRANCES C
HAPPININGS
JOLSON A
MINNELLI L
PATINKIN M
TOUCH OF CLASS


                Variations:
  MAMMY
  MAMIE
  MY MAMMA
  MAMY
  MY MUMMY
  MY MAMMY IWF
  MI MAMI INCI.
  MUMMY

                Publishers/Administrators:
  BOURNE CO
    % MS BEEBE BOURNE
    5 WEST 37TH STREET
    6TH FLOOR
    NEW YORK , NY, 10018
    Tel. (212) 391-4300

  DONALDSON PUBLISHING CO
    C/O SUSSMAN & ASSOCIATES
    1222 16TH AVENUE SOUTH
    3RD FLOOR
    NASHVILLE , TN, 37212
    Tel. (615) 320-9161

  WAROCK CORPORATION
    P.O. DRAWER 940
    EAST HAMPTON, NY, 11937
    Tel. (631) 324-3600


If you still aren't convinced, just call the publishers--they'll set you straight--