diff --git a/slycot/tests/test_sg03ad.py b/slycot/tests/test_sg03ad.py
index 7b498d6a..830f3fc3 100644
--- a/slycot/tests/test_sg03ad.py
+++ b/slycot/tests/test_sg03ad.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# test_sg03ad.py - test suit for stability margin commands
+# test_sg03ad.py - test suite for stability margin commands
 # RvP, 15 Jun 2017
 from __future__ import print_function
 
@@ -8,52 +8,67 @@
 from slycot import synthesis
 import numpy as np
 
-from numpy.testing import assert_raises, assert_almost_equal
+from numpy.testing import assert_almost_equal
 
 # test cases from
+# Penzl T., Numerical Solution of Generalized Lyapunov Equations
 # http://www.qucosa.de/fileadmin/data/qucosa/documents/4168/data/b002.pdf
 
+
 class test_sg03ad(unittest.TestCase):
 
-    def test_sg03ad_a(self):
-        # Example 1
+    def test_sg03ad_ex1c(self):
+        """ Example 1 continuous case"""
         n = 100
-        Xref = np.ones((n,n)) 
+        Xref = np.ones((n, n))
         U = np.tril(Xref)
         for t in range(0, 50, 10):
-            A = 2.0**(-t) - np.eye(n) + np.diag(range(1,n+1)) + U.T
-            E = np.eye(n) + 2**(-t)*U
+            A = (2**(-t) - 1) * np.eye(n) + np.diag(np.arange(1., n+1.)) + U.T
+            E = np.eye(n) + 2**(-t) * U
             Y = A.T.dot(Xref).dot(E) + E.T.dot(Xref).dot(A)
-            Q = np.zeros((n,n))
-            Z = np.zeros((n,n))
+            Q = np.zeros((n, n))
+            Z = np.zeros((n, n))
             A, E, Q, Z, X, scale, sep, ferr, alphar, alphai, beta = \
                 synthesis.sg03ad('C', 'B', 'N', 'N', 'L', n, A, E, Q, Z, Y)
-            assert_almost_equal(Xref, X)
-        
-    def test_sg03ad_3(self):
+            assert_almost_equal(X, Xref)
+
+    def test_sg03ad_ex1d(self):
+        """ Example 1 discrete case"""
+        n = 100
+        Xref = np.ones((n, n))
+        U = np.tril(Xref)
+        for t in range(0, 50, 10):
+            A = 2**(-t) * np.eye(n) + np.diag(np.arange(1., n+1.)) + U.T
+            E = np.eye(n) + 2**(-t) * U
+            Y = A.T.dot(Xref).dot(A) - E.T.dot(Xref).dot(E)
+            Q = np.zeros((n, n))
+            Z = np.zeros((n, n))
+            A, E, Q, Z, X, scale, sep, ferr, alphar, alphai, beta = \
+                synthesis.sg03ad('D', 'B', 'N', 'N', 'L', n, A, E, Q, Z, Y)
+            assert_almost_equal(X, Xref)
+
+    def test_sg03ad_b1(self):
+        """ SLICOT doc example / Penzl B.1 """
         n = 3
         A = np.array([[3.0, 1.0, 1.0],
                       [1.0, 3.0, 0.0],
                       [1.0, 0.0, 2.0]])
         E = np.array([[1.0, 3.0, 0.0],
-                       [3.0, 2.0, 1.0],
-                       [1.0, 0.0, 1.0]])
+                      [3.0, 2.0, 1.0],
+                      [1.0, 0.0, 1.0]])
         Y = np.array([[64.0, 73.0, 28.0],
-                       [73.0, 70.0, 25.0],
-                       [28.0, 25.0, 18.0]])
+                      [73.0, 70.0, 25.0],
+                      [28.0, 25.0, 18.0]])
         Xref = np.array([[-2.0000, -1.0000, 0.0000],
-                          [-1.0000, -3.0000, -1.0000],
-                          [0.0000, -1.0000, -3.0000]])
-        Q = np.zeros((3,3))
-        Z = np.zeros((3,3))
+                         [-1.0000, -3.0000, -1.0000],
+                         [0.0000, -1.0000, -3.0000]])
+        Q = np.zeros((3, 3))
+        Z = np.zeros((3, 3))
         A, E, Q, Z, X, scale, sep, ferr, alphar, alphai, beta = \
             synthesis.sg03ad('C', 'B', 'N', 'N', 'L', n, A, E, Q, Z, -Y)
-        #print(A, E, Q, Z, X, scale, sep)
+        # print(A, E, Q, Z, X, scale, sep)
         assert_almost_equal(X, Xref)
 
-def suite():
-   return unittest.TestLoader().loadTestsFromTestCase(TestConvert)
-
 
 if __name__ == "__main__":
     unittest.main()