Jans Koster (born 1938) is a retired Dutch freestyle swimmer. <unk> <unk> <unk>
1958 European Aquatics Championships (400 m) and set two European and two world records in 1500 m in 1956<unk>1957. ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️