. . "P.G Hoekstra" . "P.G" . "P. Gerrit Hoekstra" . "P. Gerrit Hoekstra" . "G." . "P." . "P.G." . . "P.G. Hoekstra" . "Gerrit Hoekstra"@en . "Hoekstra, Gerrit (P. Gerrit)" . . . "P. G. Hoekstra" . "Gerrit" . "P. Gerrit" . . "Gerrit" . "Hoekstra" .