Hyperlink DOIs against preferred resolver

unsupported/Eigen/CXX11/src/Tensor/TensorIntDiv.h

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorIntDiv.h b/unsupported/Eigen/CXX11/src/Tensor/TensorIntDiv.h
index fb64546..bf5c532 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorIntDiv.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorIntDiv.h
@@ -21,7 +21,7 @@
   * \brief Fast integer division by a constant.
   *
   * See the paper from Granlund and Montgomery for explanation.
-  *   (at http://dx.doi.org/10.1145/773473.178249)
+  *   (at https://doi.org/10.1145/773473.178249)
   *
   * \sa Tensor
   */

unsupported/Eigen/src/IterativeSolvers/DGMRES.h

diff --git a/unsupported/Eigen/src/IterativeSolvers/DGMRES.h b/unsupported/Eigen/src/IterativeSolvers/DGMRES.h
index bae04fc..d603ba3 100644
--- a/unsupported/Eigen/src/IterativeSolvers/DGMRES.h
+++ b/unsupported/Eigen/src/IterativeSolvers/DGMRES.h
@@ -89,7 +89,7 @@
  * [1] D. NUENTSA WAKAM and F. PACULL, Memory Efficient Hybrid
  *  Algebraic Solvers for Linear Systems Arising from Compressible
  *  Flows, Computers and Fluids, In Press,
- *  http://dx.doi.org/10.1016/j.compfluid.2012.03.023   
+ *  https://doi.org/10.1016/j.compfluid.2012.03.023   
  * [2] K. Burrage and J. Erhel, On the performance of various 
  * adaptive preconditioned GMRES strategies, 5(1998), 101-121.
  * [3] J. Erhel, K. Burrage and B. Pohl, Restarted GMRES