Simplify the following text for a Grade 14 native English-speaking person.
Original: ` In the 1980s Phelps increased collaboration with European universities and institutions , including Banca d'Italia ( where he spent most of his 1985-86 sabbatical and Observatoire FranÃ ais des Conjonctures Ã conomiques ( OFCE ) .
Simplified: In the 1980s Professor Phelps worked with European universities and institutions , such as Banca d'Italia ( most of his 1985-86 holidays were spent in Italy ) and Observatoire FranÃ ais des Conjonctures Ã conomiques ( OFCE ) .