Robert Phelps
... that Robert Phelps is a "grandfather" of modern variational principles, according to Ivar Ekeland?
... that <b id="mwDaM"><a href="./Robert_Phelps" id="mwDaQ" rel="mw:WikiLink" title="Robert Phelps">Robert Phelps</a></b> is a "grandfather" of <a href="./Ekeland's_variational_principle" id="mwDaU" rel="mw:WikiLink" title="Ekeland's variational principle">modern variational principles</a>, according to <a href="./Ivar_Ekeland" id="mwDaY" rel="mw:WikiLink" title="Ivar Ekeland">Ivar Ekeland</a>?