Add NASA 9-coefficient reference

doc/doxygen/cantera.bib

@@ -186,6 +186,14 @@ @article{mason1983
     publisher = {Elsevier},
     title = {Gas Transport in Porous Media: the Dusty-Gas Model},
     year = {1983}}
+@techreport{mcbride2002,
+    author = {B.~J.~McBride and M.~J.~Zehe and S.~Gordon},
+    title = {{NASA} {Glenn} coefficients for calculating thermodynamic properties
+        of individual species},
+    institution = {National Aeronautics and Space Administration},
+    number = {NASA/TP-2002-211556},
+    url = {https://ntrs.nasa.gov/citations/20020085330},
+    year = {2002}}
 @article{monchick1961,
     author = {L.~Monchick and E.~A.~Mason},
     title = "{Transport Properties of Polar Gases}",

include/cantera/thermo/Nasa9Poly1.h

@@ -23,11 +23,8 @@ namespace Cantera
 /*!
  * This parameterization expresses the heat capacity via a 7 coefficient
  * polynomial. Note that this is the form used in the 2002 NASA equilibrium
- * program. A reference to the form is provided below:
- *
- * "NASA Glenn Coefficients for Calculating Thermodynamic Properties of
- * Individual Species," B. J. McBride, M. J. Zehe, S. Gordon
- * NASA/TP-2002-211556, Sept. 2002
+ * program. A reference to the form is provided in McBride, et al.
+ * @cite mcbride2002.
  *
  * Nine coefficients @f$ (a_0,\dots,a_8) @f$ are used to represent
  * @f$ C_p^0(T) @f$, @f$ H^0(T) @f$, and @f$ S^0(T) @f$ as