sentence1: Ralph R. B. von Frese is an American geophysicist at Ohio State University who , in collaboration with Laramie Potts , identified the mass concentration in Wilke 's land in Antarctica .
sentence2: Laramie Potts is an American geophysicist at Ohio State University who , in collaboration with Ralph R. B. von Frese , identified the mass concentration of Wilke 's land in Antarctica .