/**
- * Implementation of the error indicator by Kelly, Gago, Zienkiewicz and
+ * Implementation of the error indicator by Kelly, De S. R. Gago, Zienkiewicz and
* Babuska. This error indicator tries to approximate the error per cell by
* integration of the jump of the gradient of the solution along the faces of
* each cell. It can be understood as a gradient recovery estimator; see the
- * survey of Ainsworth for a complete discussion.
+ * survey of Ainsworth and Oden, "A Posteriori Error Estimation in Finite Element
+ * Analysis" (Wiley, 2000) for a complete discussion.
*
* @note In spite of the name, this is not truly an a posteriori error
* estimator, even if applied to the Poisson problem only. It gives good hints
* the conormal derivative $a\frac{du}{dn} = g$.
*
* The error estimator returns a vector of estimated errors per cell which can
- * be used to feed the <tt>Triangulation<dim>::refine_*</tt> functions. This
+ * be used to feed the GridRefinement::refine_fixed_fraction,
+ * GridRefinement::refine_fixed_number, and similar functions. This
* vector contains elements of data type @p float, rather than @p double,
- * since accuracy is not so important here, and since this can save rather a
- * lot of memory, when using many cells.
+ * since accuracy is not important in the current context.
+ *
+ * The full reference for the paper in which this error estimator is defined
+ * is as follows:
+ * @code
+ * @Article{KGZB83,
+ * author = {Kelly, D. W. and {De S. R. Gago}, J. P. and Zienkiewicz, O. C.
+ * and Babu\v{s}ka, I.},
+ * title = {A posteriori error analysis and adaptive processes
+ * in the finite element method: Part {I}--Error Analysis},
+ * journal = {Int. J. Num. Meth. Engrg.},
+ * year = {1983},
+ * volume = {19},
+ * pages = {1593--1619}
+ * }
+ * @endcode
*
*
* <h3>Implementation</h3>