Table schema:
CREATE TABLE table_name_30 (nationality VARCHAR, previous_team VARCHAR, years_of_nba_experience_ VARCHAR, a_ VARCHAR)

Question: Which Nationality has a Previous team of new york knicks, and more than 3 Years of NBA experience?
SQL: SELECT nationality FROM table_name_30 WHERE previous_team = "new york knicks" AND years_of_nba_experience_[a_] > 3