diff --git a/.gitignore b/.gitignore
index b848395..1498391 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,7 +13,7 @@
 /new/
 /new.*/
 # ---------------------------------------------------------------------------
-# soruce code
-/CppAD-20190200.0.tar.gz
-# documentation
-/CppAD-20190200.doc.tar.gz
+# source code tarball creates CppAD-20190200.0
+/20190200.0.tar.gz
+# documentation tarball creates CppAD-20190200.doc
+/20190200.doc.tar.gz
diff --git a/cppad.spec b/cppad.spec
index 8416f86..40be18a 100644
--- a/cppad.spec
+++ b/cppad.spec
@@ -31,13 +31,10 @@ Summary: C++ Algorithmic Differentiation (AD), %{name}-devel and %{name}-doc
 # change (see mention of cppad_lib below).
 %global debug_package %{nil}
 
-
-# Note that the upstream sources have been named the same as thier directories;
-# CppAD-%%{version} and CppAD-%%{yyyymmdd}.doc
 License: EPL2.0 or (GPL2 or later)
 URL: http://coin-or.github.io/CppAD
-Source: https://github.com/coin-or/CppAD/archive/%{version}.tar.gz
-Source1: https://github.com/coin-or/CppAD/archive/%{yyyymmdd}.doc.tar.gz
+Source1: https://github.com/coin-or/CppAD/archive/%{version}.tar.gz
+Source2: https://github.com/coin-or/CppAD/archive/%{yyyymmdd}.doc.tar.gz
 BuildRequires:  gcc
 BuildRequires:  gcc-c++
 BuildRequires: cmake >= 2.8
@@ -81,15 +78,15 @@ The documentation, for the most recent version of %{name}, can be found at
 # -----------------------------------------------------------------------------
 %prep
 #
-# The source code tarball
+# This source code tarball creates CppAD-%%{version}
 rm -rf CppAD-%{version}
-tar -xzf %{_topdir}/SOURCES/CppAD-%{version}.tar.gz
+tar -xzf %{_topdir}/SOURCES/%{version}.tar.gz
 #
-# The documentation tarball
+# This documentation tarball creates CppAD-%%{yyymmdd}.doc
 rm -rf CppAD-%{yyyymmdd}.doc
-tar -xzf %{_topdir}/SOURCES/CppAD-%{yyyymmdd}.doc.tar.gz
+tar -xzf %{_topdir}/SOURCES/%{yyyymmdd}.doc.tar.gz
 #
-# move the documentaion to this build directory
+# move the documentaion to the build directory
 mv CppAD-%{yyyymmdd}.doc/doc CppAD-%{version}/doc
 mv CppAD-%{version}/COPYING  COPYING
 mv CppAD-%{version}/uw_copy_040507.html uw_copy_040507.html
@@ -103,12 +100,12 @@ sed  -e "s|\${cppad_SOURCE_DIR}/include|SYSTEM $includedir|" \
 # build
 # -----------------------------------------------------------------------------
 %build
-# See https://fedoraproject.org/wiki/Packaging:Cmake?rd=Packaging/cmake
-# and http://www.coin-or.org/CppAD/Doc/cmake.htm
 #
 # Cannot use %%{_includedir}, $${_libdir}, %%{_datadir}, %%{_docdir} 
 # because they are absolute paths. Relative values would be more flexible 
 # because they can be combined with %%{_prefix} to get absolute values.
+# The last argument to the cmake command is the directory created using 
+# the souce code tarball.
 cppad_cxx_flags='-Wall -pedantic-errors -std=c++11 -Wshadow -Wconversion'
 %cmake --version
 %cmake \
@@ -138,6 +135,7 @@ cppad_cxx_flags='-Wall -pedantic-errors -std=c++11 -Wshadow -Wconversion'
     -D cppad_tape_addr_type=size_t \
     -D cppad_deprecated=NO \
     CppAD-%{version}
+#
 make %{?_smp_mflags}
 
 # -----------------------------------------------------------------------------
@@ -148,12 +146,14 @@ rm -rf %{buildroot}
 make install DESTDIR=%{buildroot}
 
 %files devel
-%doc COPYING uw_copy_040507.html
 %{_includedir}/%{name}
 %{_datadir}/pkgconfig/%{name}.pc
 %{_libdir}/pkgconfig/%{name}.pc
+# These documentation files come from the source code tarball
+%doc COPYING uw_copy_040507.html
 
 %files doc
+# These documentation files come from the docukentation tarball
 %{_docdir}/%{name}
 
 # -----------------------------------------------------------------------------
diff --git a/sources b/sources
index 44c42c8..2085b5e 100644
--- a/sources
+++ b/sources
@@ -1,2 +1,2 @@
-SHA512 (CppAD-20190200.0.tar.gz) = 2cd77d56b141f58f5bf2bfc75b17ac663e6f5696f43bb18219e94289000f45acb148eee2dec445813aada01e55ed560888e69f8c32ced359df5472938efec6a8
-SHA512 (CppAD-20190200.doc.tar.gz) = 7543960efd81fbf0186397b63953b927ec5cfd1f0796408b63ddbf5d41a2137ce1fa1e03ad1448eb31b131cce2c58bd4a52f47ea52da6506126b74eb539e43ba
+SHA512 (20190200.0.tar.gz) = 2cd77d56b141f58f5bf2bfc75b17ac663e6f5696f43bb18219e94289000f45acb148eee2dec445813aada01e55ed560888e69f8c32ced359df5472938efec6a8
+SHA512 (20190200.doc.tar.gz) = 7543960efd81fbf0186397b63953b927ec5cfd1f0796408b63ddbf5d41a2137ce1fa1e03ad1448eb31b131cce2c58bd4a52f47ea52da6506126b74eb539e43ba