diff --git a/src/sage/combinat/sf/dual.py b/src/sage/combinat/sf/dual.py
index aae10602f2d..207e411a2c6 100644
--- a/src/sage/combinat/sf/dual.py
+++ b/src/sage/combinat/sf/dual.py
@@ -292,7 +292,7 @@ def basis_name(self):
         Return the name of the basis of ``self``.
 
         This is used for output and, for the classical bases of
-        symmetric functions, to connect this basis with Symmetrica.
+        symmetric functions, to connect this basis with :ref:`Symmetrica <spkg_symmetrica>`.
 
         EXAMPLES::
 
diff --git a/src/sage/combinat/sf/sfa.py b/src/sage/combinat/sf/sfa.py
index d569b6ce1dd..05abd332b08 100644
--- a/src/sage/combinat/sf/sfa.py
+++ b/src/sage/combinat/sf/sfa.py
@@ -641,7 +641,8 @@ def corresponding_basis_over(self, R):
                 sage: Sym = SymmetricFunctions(P)
                 sage: mj = Sym.macdonald().J()
                 sage: mj.corresponding_basis_over(Integers(13)['q','t'])
-                Symmetric Functions over Multivariate Polynomial Ring in q, t over Ring of integers modulo 13 in the Macdonald J basis
+                Symmetric Functions over Multivariate Polynomial Ring in q, t over
+                 Ring of integers modulo 13 in the Macdonald J basis
 
             TESTS:
 
diff --git a/src/sage/combinat/sf/witt.py b/src/sage/combinat/sf/witt.py
index 37a07f8139f..c856e8fe399 100644
--- a/src/sage/combinat/sf/witt.py
+++ b/src/sage/combinat/sf/witt.py
@@ -23,7 +23,6 @@
 from sage.arith.misc import divisors
 from sage.combinat.integer_lists.invlex import IntegerListsLex
 from sage.combinat.partitions import ZS1_iterator
-from sage.matrix.constructor import matrix
 from sage.misc.cachefunc import cached_method