diff --git a/dlib/matrix/symmetric_matrix_cache.h b/dlib/matrix/symmetric_matrix_cache.h
index 7c017088f..6e26dd937 100644
--- a/dlib/matrix/symmetric_matrix_cache.h
+++ b/dlib/matrix/symmetric_matrix_cache.h
@@ -177,7 +177,7 @@ namespace dlib
             init();
             make_sure_next_is_unreferenced();
 
-            // if the lookup table is pointing to cache(next,*) then clear lookup[next]
+            // if the lookup table is pointing to cache[next] then clear lookup[next]
             if (rlookup[next] != -1)
                 lookup[rlookup[next]] = -1;
 
diff --git a/dlib/optimization/optimization_solve_qp2_using_smo_abstract.h b/dlib/optimization/optimization_solve_qp2_using_smo_abstract.h
index 24731d781..383033b10 100644
--- a/dlib/optimization/optimization_solve_qp2_using_smo_abstract.h
+++ b/dlib/optimization/optimization_solve_qp2_using_smo_abstract.h
@@ -71,8 +71,8 @@ namespace dlib
                   Where f is convex.  This means that Q should be symmetric and positive-semidefinite.
                 
                 
-                This object implements the strategy used by the LIBSVM tool and described 
-                by the following papers:
+                This object implements the strategy used by the LIBSVM tool.  The following papers
+                can be consulted for additional details:
                     - Chang and Lin, Training {nu}-Support Vector Classifiers: Theory and Algorithms
                     - Chih-Chung Chang and Chih-Jen Lin, LIBSVM : a library for support vector 
                       machines, 2001. Software available at http://www.csie.ntu.edu.tw/~cjlin/libsvm