Index: src/natools-s_expressions-atom_buffers.ads
==================================================================
--- src/natools-s_expressions-atom_buffers.ads
+++ src/natools-s_expressions-atom_buffers.ads
@@ -20,21 +20,15 @@
 -- single Atom object.                                                      --
 -- It also provides an individual Octet accessor, used in parser internal   --
 -- recursive buffer.                                                        --
 ------------------------------------------------------------------------------
 
-with Natools.References;
-with Natools.Storage_Pools;
+with Natools.S_Expressions.Atom_Refs;
 
 package Natools.S_Expressions.Atom_Buffers is
    pragma Preelaborate (Atom_Buffers);
 
-   package Atom_Refs is new Natools.References
-     (Atom,
-      Storage_Pools.Access_In_Default_Pool'Storage_Pool,
-      Storage_Pools.Access_In_Default_Pool'Storage_Pool);
-
    type Atom_Buffer is tagged private;
 
    procedure Preallocate (Buffer : in out Atom_Buffer; Length : in Count);
       --  Preallocate enough memory to append Length octets without
       --  any further allocation.

ADDED   src/natools-s_expressions-atom_refs.ads
Index: src/natools-s_expressions-atom_refs.ads
==================================================================
--- src/natools-s_expressions-atom_refs.ads
+++ src/natools-s_expressions-atom_refs.ads
@@ -0,0 +1,29 @@
+------------------------------------------------------------------------------
+-- Copyright (c) 2014, Natacha Porté                                        --
+--                                                                          --
+-- Permission to use, copy, modify, and distribute this software for any    --
+-- purpose with or without fee is hereby granted, provided that the above   --
+-- copyright notice and this permission notice appear in all copies.        --
+--                                                                          --
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES --
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         --
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  --
+-- ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   --
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    --
+-- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  --
+-- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           --
+------------------------------------------------------------------------------
+
+------------------------------------------------------------------------------
+-- Natools.S_Expressions.Atom_Refs provides a common instance of default    --
+-- reference-counted atoms.                                                 --
+------------------------------------------------------------------------------
+
+with Natools.References;
+with Natools.Storage_Pools;
+
+package Natools.S_Expressions.Atom_Refs is new Natools.References
+  (Natools.S_Expressions.Atom,
+   Natools.Storage_Pools.Access_In_Default_Pool'Storage_Pool,
+   Natools.Storage_Pools.Access_In_Default_Pool'Storage_Pool);
+pragma Preelaborate (Natools.S_Expressions.Atom_Refs);

Index: src/natools-s_expressions-interpreters.ads
==================================================================
--- src/natools-s_expressions-interpreters.ads
+++ src/natools-s_expressions-interpreters.ads
@@ -26,11 +26,11 @@
 ------------------------------------------------------------------------------
 
 with Natools.S_Expressions.Lockable;
 
 private with Ada.Containers.Indefinite_Ordered_Maps;
-private with Natools.S_Expressions.Atom_Buffers;
+private with Natools.S_Expressions.Atom_Refs;
 
 generic
    type Shared_State (<>) is limited private;
    type Shared_Context (<>) is limited private;
 
@@ -119,9 +119,9 @@
      (Atom, Command'Class, Less_Than);
 
    type Interpreter is new Command with record
       Commands : Command_Maps.Map;
       Max_Length : Count := 0;
-      Fallback_Name : Atom_Buffers.Atom_Refs.Reference;
+      Fallback_Name : Atom_Refs.Reference;
    end record;
 
 end Natools.S_Expressions.Interpreters;