Update index.rst

Author: Martin Gallo

docs/user/index.rst

@@ -107,5 +107,5 @@ Documentation on the SAP CAR file protocol is available in SAP's `Virus Scan Int
 `specification document <ftp://ftp.sap.com/pub/icc/nw-vsi/VSA-Specification.pdf>`_. An example implementation can be
 also found in the `Virus Scan Adapter SDK <ftp://ftp.sap.com/pub/icc/nw-vsi/VSA-SDK-2.0.zip>`_.
 
-Initial research about the IGS protocol was performed by Yvan Genuer and published in ``_.
+Initial research about the IGS protocol was performed by Yvan Genuer and published in `SAP IGS : The 'vulnerable' forgotten component <https://www.troopers.de/troopers18/agenda/3r38lr/>`_.