april 1957

april 1957: 40 companies

1. april 1957 5 companies

2. april 1957 1 companies

3. april 1957 2 companies

5. april 1957 2 companies

8. april 1957 1 companies

9. april 1957 2 companies

10. april 1957 1 companies

11. april 1957 2 companies

12. april 1957 1 companies

15. april 1957 2 companies

16. april 1957 2 companies

17. april 1957 4 companies

18. april 1957 3 companies

23. april 1957 3 companies

24. april 1957 3 companies

25. april 1957 1 companies

26. april 1957 4 companies

30. april 1957 1 companies