"Valkhoff, Jaap (1910-1992)" . "Jaap Valkhoff" . _:Bce47846d68123656407f73f0536af4d1 . . "1910"^^ . "1992"^^ . . "Jaap" . "Valkhoff" . . "Valkhoff, Jacobus" . _:Bce47846d68123656407f73f0536af4d1 . _:Bce47846d68123656407f73f0536af4d1 . _:Bce47846d68123656407f73f0536af4d1 "2023-05-22"^^ . _:Bce47846d68123656407f73f0536af4d1 . _:Bce47846d68123656407f73f0536af4d1 . _:Bce47846d68123656407f73f0536af4d1 "329320777" . _:Bce47846d68123656407f73f0536af4d1 . _:Bce47846d68123656407f73f0536af4d1 . _:Bce47846d68123656407f73f0536af4d1 .