 Complete the following phrase:  Born in Zaandam, Koeman began his career at Groningen before transferring to the Netherlands most successful club Ajax in 1983, where he won the national Eredivisie title in 198485. He then joined Ajaxs rivals PSV Eindhoven in 1986, winning three consecutive Eredivisie titles 198687, 198788 and 198889 and the European Cup in 1988. Ronald Koeman is one of five European players to ever win a treble with their club and a cup with their national team in the same year. The other four players are his teammates Hans van Breukelen, Berry van Aerle, Gerald Vanenburg and Wim Kieft. In 1989, Koeman moved to Barcelona and became part of Johan Cruyffs Dream Team, helping the club win La Liga four years in a row between 1991 and 1994, and the 199192 European Cup, where he scored the winning goal of 