Parse this person name:

Geert Oestrovsky (1921-1987, flourished 1950-1975)
user
first_name: Geert
last_name: Oestrovsky
middle_names: []
temporal:
- start: 1921
  end: 1987
  type: life_span
- start: 1950
  end: 1975
  type: flourished
titles: []
extra_info: []
assistant