diff --git a/trestle/tasks/oscal_catalog_to_csv.py b/trestle/tasks/oscal_catalog_to_csv.py
index b68ed8457..0003321b0 100644
--- a/trestle/tasks/oscal_catalog_to_csv.py
+++ b/trestle/tasks/oscal_catalog_to_csv.py
@@ -70,16 +70,11 @@ def convert_control_id(control_id: str) -> str:
 
 def convert_smt_id(smt_id: str) -> str:
     """Convert smt id."""
-    parts = smt_id.split('_smt')
-    seg1 = convert_control_id(parts[0])
-    seg2 = ''
-    if len(parts) == 2:
-        seg2 = parts[1]
-        if '.' in seg2:
-            seg2 = seg2.replace('.', '(')
-            seg2 = seg2 + ')'
-    rval = f'{seg1}{seg2}'
-    return rval
+    parts = smt_id.split('_')
+    control_id = convert_control_id(parts[0])
+    sub_ids = parts[1].split('.')[1:]
+    sub_id = ''.join(f'({s})' for s in sub_ids)
+    return f'{control_id}{sub_id}'
 
 
 class CsvHelper:
@@ -118,6 +113,15 @@ def _init_control_parent_map(self, recurse=True) -> None:
                     raise RuntimeError('{parent} duplicate?')
                 self._control_parent_map[parent] = control
 
+    def derive_text(self, control: Control, part: Part) -> Optional[str]:
+        """Derive control text."""
+        rval = None
+        if part.prose:
+            id_ = self._derive_id(part.id)
+            text = self._resolve_parms(control, part.prose)
+            rval = join_str(id_, text)
+        return rval
+
     def get_parent_control(self, ctl_id: str) -> Control:
         """Return parent Control of child Control.id, if any."""
         return self._control_parent_map.get(ctl_id)
@@ -141,16 +145,6 @@ def get_statement_text_for_control(self, control: Control) -> Optional[str]:
         statement_text = self._withdrawn(control)
         return statement_text
 
-    def get_statement_text_for_part(self, control: Control, part: Part) -> Optional[str]:
-        """Get statement text for part."""
-        statement_text = self._derive_text(control, part)
-        if part.parts:
-            for subpart in part.parts:
-                if '_smt' in subpart.id:
-                    partial_text = self._derive_text(control, subpart)
-                    statement_text = join_str(statement_text, partial_text)
-        return statement_text
-
     def _withdrawn(self, control: Control) -> Optional[str]:
         """Check if withdrawn."""
         rval = None
@@ -192,15 +186,6 @@ def _href_to_control(self, href: str) -> str:
         rval = href.replace('#', '').upper()
         return rval
 
-    def _derive_text(self, control: Control, part: Part) -> Optional[str]:
-        """Derive control text."""
-        rval = None
-        if part.prose:
-            id_ = self._derive_id(part.id)
-            text = self._resolve_parms(control, part.prose)
-            rval = join_str(id_, text)
-        return rval
-
     def _derive_id(self, id_: str) -> str:
         """Derive control text sub-part id."""
         rval = None
@@ -319,30 +304,24 @@ def _get_content_by_statement(self) -> List:
                 self.add(row)
         return self.rows
 
-    def _add_subparts_by_statement(self, control: Control, part: Part) -> None:
-        """Add subparts by statement."""
+    def _add_statements_recursively(self, control: Control, part: Part) -> None:
+        """Add parts and subparts recursively."""
         catalog_helper = self.catalog_helper
         control_id = convert_control_id(control.id)
-        for subpart in part.parts:
-            if '_smt' in subpart.id:
-                statement_text = catalog_helper.get_statement_text_for_part(control, subpart)
-                row = [control_id, control.title, convert_smt_id(subpart.id), statement_text]
-                self.add(row)
+        
+        if part.id and '_smt' in part.id:
+            statement_text = catalog_helper.derive_text(control, part)
+            row = [control_id, control.title, convert_smt_id(part.id), statement_text]
+            self.add(row)
+        
+        if part.parts:
+            for subpart in part.parts:
+                self._add_statements_recursively(control, subpart)
 
     def _add_parts_by_statement(self, control: Control) -> None:
         """Add parts by statement."""
-        catalog_helper = self.catalog_helper
-        control_id = convert_control_id(control.id)
         for part in control.parts:
-            if part.id:
-                if '_smt' not in part.id:
-                    continue
-                if part.parts:
-                    self._add_subparts_by_statement(control, part)
-                else:
-                    statement_text = catalog_helper.get_statement_text_for_part(control, part)
-                    row = [control_id, control.title, convert_smt_id(part.id), statement_text]
-                    self.add(row)
+            self._add_statements_recursively(control, part)
 
     def _get_content_by_control(self) -> List:
         """Get content by statement."""