00325nam a2200121Ia 4500082001900000100002600019245006100045260003600106300001400142490003700156500000500193700000500198  a519.5bL386.EF  aLeuritzen, Steffen L.  aExtremal families and systems of sufficient statisticsb  aNew YorkbSpringer-Verlagc1988  axv, 268p.  aLecture notes in Statisticsv 49  a  a