Update citations.

doc/citations/sixteen.bib

@@ -1,3 +1,15 @@
+% http://www.osti.gov/scitech/biblio/1291258
+@TechReport{Andersson_2016,
+  author      = {A.~D.~Andersson and R.~T.~Perriot and G.~Pastore and M.~R.~Tonks and M.~W.~Cooper and X.-Y.~Liu and A.~Goyal and B.~P.~Uberuaga and C.~R.~Stanek},
+  title       = {{Report on simulation of fission gas and fission product diffusion in UO$_2$}},
+  institution = {Los Alamos National Laboratory},
+  day         = 22,
+  month       = jul,
+  year        = 2016,
+  number      = {LA-UR--15-28086},
+  note        = {\url{http://dx.doi.org/10.2172/1291258}}
+}
+
 @Article{DGuillen_2016,
    author = {D.~P.~Guillen and W.~H.~Harris},
     title = {{Measurement and simulation of thermal conductivity of hafnium-aluminum thermal neutron absorber material}},