diff --git a/TS-0041-oneM2M-SensorThings_interworking.md b/TS-0041-oneM2M-SensorThings_interworking.md
index cef31708bf5ee296a6ae76e9a2b15fc58d8b91f5..0a657aeb4251186786e1ff2814bb3b81c31a9485 100644
--- a/TS-0041-oneM2M-SensorThings_interworking.md
+++ b/TS-0041-oneM2M-SensorThings_interworking.md
@@ -73,6 +73,7 @@ References are either specific (identified by date of publication and/or edition
 
  
 - <a name="_ref_1">[1]</a>    OGC SensorThings API "Part 1: Sensing Version 1.1" (http://www.opengis.net/doc/is/sensorthings/1.1)
+- <a name="_ref_2">[2]</a>    oneM2M TS-0033 (V3.0.0): "Interworking Framework"
 
 ## 2.2 Informative references
 
@@ -174,6 +175,7 @@ The Sensing Entities data model and the purpose of data within the data model di
 -	Data embedded in the Sensing Entities Data Model, like "historic locations" should be seen as data for documentation purposes.
 
 
+
 # 6 Architecture Model of OGC/STA to oneM2M interworking
 
 ## 6.0 Introduction
@@ -189,12 +191,16 @@ The basic interworking enables applications that are connected to an oneM2M-base
 
 ## 6.1 OGC/STA-to-oneM2M Data Model Mapping
 
-According to oneM2M TS-0033 [i.4] a representation of a non-oneM2M Proximal IoT function/device in a oneM2M-specified resource instance is to be synchronized with the entity that it represents.
-This means that the OGC/STA data model is represented in the hosting CSE. The data in the OGC/STA server are organized as Sensing Entities [i.3] (see Figure 5.1-1: STA Sensing Entities data model).
+According to oneM2M TS-0033 <a href="#_ref_2">[2]</a> a representation of a non-oneM2M Proximal IoT function/device in a oneM2M-specified resource instance is to be synchronized with the entity that it represents.
+This means that the OGC/STA data model is represented in the hosting CSE. The data in the OGC/STA server are organized as Sensing Entities <a href="#_ref_1">[1]</a> (see Figure 5-2: STA Sensing Entities data model).
 The oneM2M structure for data models is a tree-structure where data are organized in containers or trees of containers. 
-The OGC/STA data model is a relational one, as used in databases, and not hierarchical. Thus, it creates a challenge for full interworking of all data captured in the OGC/STA data model. 
+The OGC/STA data model is a relational one, as used in databases, and not hierarchical. Thus, it creates a challenge for full interworking of all data captured in the OGC/STA data model. In this technical specification, only a limited set of data is mapped between OGC/STA and oneM2M.
 
 
+<figure>
+  <img src="media/ogc_non_model.png" alt="non_mapping">
+  <figcaption>Figure 6.1-1: OGC data model cannot directly be mapped to oneM2M</figcaption>
+</figure>
 
 
 <mark>The following text is to be used when appropriate:</mark>