ORA-00933: SQL command not properly ended

I have a query that succeed in postgres but it fails in oracle and I don't know why?

select v.articolo,fs.descrizione as
fontes,s.articolo,s.importo_min,s.importo_max from norma as s join norma as v on s.id = v.id_norma_sanzionatoria join fonte as fv on v.id_fonte=fv.id join fonte as fs on s.id_fonte=fs.id;

      articolo | fontes | articolo | importo_min | importo_max

------------------+--------------+---------------+-------------+-------------
  articolo violata | DLG 431/2008 | sanzionatoria | 700.00 |      800.00

select v.articolo,fs.descrizione as
fontes,s.articolo,s.importo_min,s.importo_max from norma as s join norma as v on s.id = v.id_norma_sanzionatoria join fonte as fv on v.id_fonte=fv.id join fonte as fs on s.id_fonte=fs.id;

cx_Oracle.DatabaseError: ORA-00933: SQL command not properly ended

--
http://www.freelists.org/webpage/oracle-l