Molhuysen (L'Empereur (Constantijn) van de or ab Oppick or Opwij(c)k, he called himself also Imperator)
Rooden, P.T. van. Theology, biblical scholarship, and rabbinical studies in the seventeenth century, 1989 CIP t.p. (Constantijn L'Empereur (1591-1648) professor of Hebrew and theology at Leiden)