00245nam a2200097Ia 4500008004100000040001100041100002600052245001100078260004500089300001300134251112s9999||||xx |||||||||||||| ||und||  aCNCLSA  aProfessor R. B. Clark 0aNature  c1955bMacmillan Journals LimitedaLondon  aP. 1-345