Passage: In 1988, Johan Cruyff returned to the club, this time as manager and he assembled what would later be dubbed the "Dream Team". He used a mix of Spanish players like Pep Guardiola, José Mari Bakero, Jon Andoni Goikoetxea, Miguel Angel Nadal and Txiki Begiristain while signing international players such as Ronald Koeman, Michael Laudrup, Romário and Hristo Stoichkov.

Question: Who were the four international players signed?
Ronald Koeman, Michael Laudrup, Romário and Hristo Stoichkov