qZeta: Corrected form of the first coefficient in the zeta equation

Added original reference

src/turbulenceModels/incompressible/RAS/qZeta/qZeta.C

@@ -308,7 +308,7 @@ void qZeta::correct()
       - fvm::laplacian(DzetaEff(), zeta_)
      ==
         (2.0*C1_ - 1)*G*zeta_/q_
-      - fvm::Sp((2.0*C2_ - dimensionedScalar(1.0))*f2()*zeta_/q_, zeta_)
+      - fvm::SuSp((2.0*C2_*f2() - dimensionedScalar(1.0))*zeta_/q_, zeta_)
       + E
     );
 

src/turbulenceModels/incompressible/RAS/qZeta/qZeta.H

@@ -28,6 +28,19 @@ Description
     Gibson and Dafa'Alla's q-zeta two-equation low-Re turbulence model
     for incompressible flows
 
+    References:
+    \verbatim
+        "Calculation of oscillating boundary layers with the
+        q-[zeta] turbulence model"
+        A.A. Dafa'Alla, E. Juntasaro and M.M. Gibson
+
+        Engineering Turbulence Modelling and Experiments 3:
+        Proceedings of the Third International Symposium,
+        Crete, Greece, May 27-29, 1996, p. 141.
+
+        Editors: Wolfgang Rodi and G. Bergeles
+    \endverbatim
+
 SourceFiles
     qZeta.C