| Original title | Le serpent | 
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| Danish title | Spionkrigen | 
| Other titles | The serpent | 
| Leikstjórn | Henri Verneuil | 
| Screenplay | Henri Verneuil | 
| Director of Photography | Claude Renoir | 
| Editor | Pierre Gilette | 
| Composer | Ennio Morricone | 
| Production designer | Jacques Saulnier | 
| Appearance | Yul Brynner, Henry Fonda, Dirk Bogarde | 
| Land | Tyskland, Frankrig, Italien | 
| Domestic distribution | Warner-Constantin | 
| Technical info | 35 mm, Panavision, Farve, Tone | 
| Danish theatrical release | 15.10.1973 | 
| Cinemas | Imperial | 
| Kommentar | Censurnr. 7048, 3345 m. | 
| Danish rating | Tilladt for børn over 12 år (1960-1997) | 
      Companies | 
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| Production company | Rialto Film, Les Films la Boëtie, Euro-International | 
| Domestic distribution | Warner-Constantin | 
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      Instruktion | 
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| Instruktion | Henri Verneuil | 
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      Manus | 
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| Manus | Henri Verneuil | 
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      Produktion | 
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| Produktion | Henri Verneuil | 
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      Foto | 
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| Foto | Claude Renoir | 
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      Klip | 
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| Klip | Pierre Gilette | 
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      Musik | 
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| Musik | Ennio Morricone | 
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      Produktionsdesign | 
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| Produktionsdesign | Jacques Saulnier | 
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      Medvirkende | 
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| Medvirkende | Yul Brynner | 
| Medvirkende | Henry Fonda | 
| Medvirkende | Dirk Bogarde | 
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