  .. 

  ..       (   , 1938, .70, .3, .386-406)
  ..          (   , 2001, .133, .5, .30-40)
  ..      -    (   , 1981, .113, .4, .334-340)
  ..   -     (   , 1990, .122, .1, .43-52)
  ..         -     (   , 1988, .120, .4, .344-348)
  ..        (   , 1997, .129, . 2, . 13-21)
  .. -       (   , 1994, .126, .6, .62-71,   ..)
  ..     (   , 1997, .129, .1, .12-22)
  ..    (, 1994, 8, .3-20)
  ..  .        -     (   , 1989, .121, .3, .236-244)