electronic signature

Bonjour,

Comment est-ce que je peux signed un document pdf ?
Merci.

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  Patrick DUPRÉ                      |   |
  Department of Chemistry            |   |  Phone: (44)-(0)-1904-434384
  The University of York             |   |  Fax:   (44)-(0)-1904-432516
  Heslington                         |   |
  York YO10 5DD  United Kingdom      |   |  email: patrick.dupre@???
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