Botteron, BernardDacorogna, Bernard2008-11-252008-11-252008-11-25199010.1016/0022-247X(90)90397-Xhttps://infoscience.epfl.ch/handle/20.500.14299/31650WOS:A1990CX68700019optimal foraging theoryExistence of solutions for a variational problem associated to models in optimal foraging theorytext::journal::journal article::research article