▁ ▁NAT O ▁fellow ship ▁to ▁the ▁Cav end ish ▁Labor atory , ▁at ▁the ▁University ▁of ▁Cambridge , ▁UK , ▁where ▁in ▁ 1 9 7 2 - 7 3 ▁he ▁collabor ated ▁with ▁Philip ▁W . ▁Anderson . ▁He ▁also ▁spent ▁most ▁of ▁ 1 9 7 4 ▁with ▁a ▁D F G ▁fellow ship ▁at ▁the ▁University ▁of ▁Stuttgart ▁in ▁the ▁group ▁of ▁Hermann ▁H aken ▁and ▁most ▁of ▁ 1 9 7 7 ▁at ▁Stan ford ▁University , ▁in ▁the ▁group ▁of ▁Sebastian ▁Don ia ch ▁. ▁ ▁From ▁Rome ▁he ▁was ▁called ▁to ▁Tri este ▁in ▁ 1 9 7 7 ▁by ▁Abd us ▁Sal am ▁and ▁Paolo ▁Bud in ich ▁to ▁start ▁within ▁the ▁ ▁International ▁Centre ▁for ▁The oret ical ▁Physics ▁ ▁the ▁ ▁I CT P ▁Cond ensed ▁M atter ▁Theory ▁Group , ▁now ad ays ▁fl our ishing . ▁In ▁ 1 9 8 0 ▁he ▁also ▁became ▁a ▁professor ▁at ▁the ▁newly ▁established ▁ ▁International ▁School ▁for ▁Advanced ▁Studies ▁( SI SS A ), ▁where ▁he ▁founded ▁and ▁directed ▁for ▁ 2 7 ▁years ▁the ▁Cond ensed ▁M atter ▁Theory ▁group . ▁ ▁From ▁ 1 9 7 7 ▁on wards ▁his ▁double ▁invol vement ▁with ▁SI SS A ▁and ▁I CT P ▁kept ▁him ▁in ▁Tri este , ▁with ▁the ▁exception ▁of ▁a ▁s abb at ical ▁year ▁at ▁the ▁IBM ▁Zur ich ▁Research ▁Labor atory ▁where ▁in ▁ 1 9 8 4 - 8 5 ▁he ▁also ▁collabor ated ▁with ▁K