extend references

I've added an article about Diffie-Hellman key exchange.

bib.bib

@@ -14,28 +14,39 @@
 	Title = {{RSA} (Cryptosystem) --- {W}ikipedia{,} {D}ie freie {E}nzyklop{\"a}die},
 	Year = {2016}}
 }
+
 @misc{ref2,
 	Author = {Wikipedia},
 	Note = {\url{https://de.wikipedia.org/wiki/RSA-Kryptosystem}},
 	Title = {{RSA}-{K}ryptosystem --- {W}ikipedia{,} {D}ie freie {E}nzyklop{\"a}die},
 	Year = {2016}}
 }
+
 @misc{ref3,
         author = "L. Van Houtven",
         title = "Crypto 101",
         note = "\url{https://www.crypto101.io}",
         year = "2016",
 }
+
 @misc{ref4,
         author = "Whitfield Diffie  Martin Hellman",
         title = {New Directions in Cryptographie},
         note = "\url{https://www-ee.stanford.edu/\%7Ehellman/publications/24.pdf}",
         year = "1976",
 }
+
 @misc{ref5,
         author = "R.L. Rivest und A. Shamir und L. Adleman",
         title = "A Method for Obtaining Digital Signatures and Public-Key 
                  Cryptosystems",
         note = "\url{https://people.csail.mit.edu/rivest/Rsapaper.pdf}",
         year = "1978",
-}
+}
+
+@misc{ref6,
+	Author = {Wikipedia},
+	Note = {\url{https://de.wikipedia.org/wiki/Diffie-Hellman-Schl%C3%BCsselaustausch}},
+	Title = {{D}iffie-{H}ellman-{S}chlüsselaustausch --- {W}ikipedia{,} {D}ie freie {E}nzyklop{\"a}die},
+	Year = {2016}}
+}