[Event "IBM"]
[Site "Amsterdam"]
[Date "1961.??.??"]
[Round "4"]
[White "Langeweg, Kick"]
[Black "Wolthuis, Willem"]
[Result "1-0"]

1. c4 c6 2. Nf3 Nf6 3. d4 d5 4. Nc3 dxc4 5. a4 Bf5 6. Ne5 e6 7. f3 Bb4 8. Bg5 h6 9. Bh4 c5 10. e4 Qxd4 11. Nxc4 Nxe4 12. Qxd4 cxd4 13. fxe4 Bg4 14. Ne5 O-O 15. Nxg4 dxc3 16. O-O-O Nc6 17. b3 Rac8 18. Bd3 g5 19. Nxh6+ Kg7 20. Bxg5 f6 21. Be3 Ne5 22. Kc2 Rh8 23. Rhf1 Rcf8 24. Bc4 Rxh6 25. Bxh6+ Kxh6 26. Bxe6 Kg7 27. Rd5 Re8 28. Bf5 Re7 29. Rf4 Nc6 30. Rh4 Re5 31. Rh7+ Kg8 32. Rxb7 Rxd5 33. exd5 Nd4+ 34. Kb1 a5 35. Bc2 Kf8 36. h4 1-0