He was appointed in 1957 as a teacher at the local training college in 4 hours per week in pedagogy and in the same year was appointed professor at the LOI ( Pelman Institute ) .
Van Praag was also active in many areas .
Van Praag was appointed in 1957 as a teacher at the local training college in 4 hours per week in pedagogy and in the same year was appointed professor at the LOI ( Pelman Institute ) .
Van Praag was also active in many areas .