Added sneaky interpolation functor jokes.

refs.bib

@@ -151,3 +151,24 @@
   year={2001},
   publisher={Springer Berlin Heidelberg}
 }
+
+
+
+@techreport{aronszajn1964interpolation,
+  title={Interpolation spaces and interpolation methods},
+  author={Aronszajn, Nachman and Gagliardo, Emilio},
+  year={1964}
+}
+@book{brudnyi1991interpolation,
+  title={Interpolation functors and interpolation spaces},
+  author={Brudnyi, Yu A and Krugljak, N Ya},
+  volume={47},
+  year={1991},
+  publisher={Elsevier}
+}
+@book{PietschHistory,
+  title={History of Banach spaces and linear operators},
+  author={Pietsch, Albrecht},
+  year={2007},
+  publisher={Springer}
+}