It occurs to me that River's postulate may refer to Tom Rivers, an
eminent animal virologist who worked at the Rockefeller Institute
beginning about 1920. You don't say what your thesis is about, so I
don't have a clue if this is even in the right ball park. If it is,
there is an oral history of Rivers by Saul Benison and two major works
by Rivers "Filterable Viruses" and Viral and Rickettsial Diseases of
Man". I would be interested in knowing if you find the postulate.
Muriel Lederman Biology VPI&SU