Complex sentence: In 1968 a paper was submitted to Nature on the radioisotopes found in oysters from the Irish Sea, by using gamma spectroscopy, the oysters were found to contain 141Ce, 144Ce, 103Ru, 106Ru, 137Cs, 95Zr and 95Nb.
Split into simpler sentences: In 1968 a paper was submitted to the journal "Nature", on a study of radioisotopes found in oysters from the Irish Sea, using gamma spectroscopy. The oysters were found to contain 141Ce, 144Ce, 103Ru, 106Ru, 137Cs, 95Zr and 95Nb.