MS ). ▁At ▁the ▁advice ▁of ▁Mr . ▁Ab end anon , ▁a ▁Dutch ▁who ▁was ▁sympath etic ▁to ▁those ▁from ▁Indones ia ▁or ▁what ▁was ▁called ▁Ind ië ▁at ▁the ▁time , ▁Rat ul ang i ▁applied ▁and ▁was ▁accepted ▁to ▁the ▁University ▁of ▁Zur ich ▁in ▁Switzerland . ▁In ▁ 1 9 1 9 , ▁he ▁obtained ▁a ▁doctor ate ▁in ▁mathematics ▁and ▁science ▁from ▁the ▁university . ▁ ▁National ist ▁activ ism ▁ ▁During ▁his ▁time ▁in ▁Amsterdam , ▁Rat ul ang i ▁frequently ▁met ▁with ▁S os rok art ono ▁( R . A . ▁K art ini ' s ▁brother ) ▁and ▁the ▁three ▁found ers ▁of ▁the ▁Ind ische ▁Party , ▁ ▁Ernest ▁D ouw es ▁De k ker , ▁T ji pto ▁M ango en ko eso emo , ▁and ▁So ew ardi ▁So er jan ing rat . ▁Rat ul ang i ▁was ▁also ▁active ▁in ▁the ▁association ▁for ▁Indones ian ▁students ▁( Ind ische ▁Vere enig ing ▁or ▁Per h imp un an ▁Indones ia ). ▁He ▁was ▁elected ▁as ▁chairman ▁of ▁the ▁association ▁in ▁ 1 9 1 4 . ▁He ▁invited ▁speak ers ▁who ▁were ▁sympath etic ▁to ▁the ▁Indones ian ▁cause , ▁such ▁as ▁Con rad ▁The odor ▁van ▁De vent er ▁and ▁Jacques ▁Hen rij ▁Ab end anon . ▁In ▁Switzerland , ▁he ▁was ▁active ▁in ▁the ▁Association ▁of ▁Asian ▁Stud ents ▁( Associ ations ▁d ' ét udi ants ▁asi atiques ) ▁where ▁he ▁met ▁J aw ah ar