Remove obsolete hack using book with version instead of software.

Author: baagaard-usgs

Diff for: us-geological-survey.csl

@@ -162,19 +162,6 @@ Online sources
             </group>
           </group>
         </if>
-        <else-if variable="version" type="book" match="all">
-          <group prefix=" " delimiter=", ">
-            <!--
-                -This is a hack until we have a computer program type
-                -->
-            <text variable="title"/>
-            <group prefix=" " delimiter=" ">
-              <text term="version"/>
-              <text variable="version"/>
-            </group>
-            <text variable="URL"/>
-          </group>
-        </else-if>
         <else-if type="bill book graphic legal_case legislation motion_picture song" match="any">
           <group suffix=":">
             <text variable="title" prefix=" "/>