update references

<h3>Normative references</h3>

<ul>

  <li id="[1]">[1] ETSI TS 103 264 (V3.1.1) (02-2020): "SmartM2M; Smart Applications; Reference Ontology and oneM2M Mapping".</li>

  <li id="[1]">[1] <a href="https://www.etsi.org/deliver/etsi_ts/103200_103299/103264/">ETSI TS 103 264</a>: "SmartM2M; Smart Applications; Reference Ontology and oneM2M Mapping".</li>

  <li id="[2]">[2] <a href="https://www.etsi.org/deliver/etsi_ts/103500_103599/103548/">ETSI TS 103 548</a>: "SmartM2M; SAREF reference ontology patterns".</li>

  <li id="[3]">[3] <a href="https://www.etsi.org/deliver/etsi_ts/103600_103699/103673/">ETSI TS 103 673</a>: "SmartM2M; SAREF Development Framework and Workflow, Streamlining the Development of SAREF and its Extensions".</li>

</ul>

<h3>Informative references</h3>

<ul>

  <li id="[i.1]">[i.1] ETSI TR 103 411 (V1.1.1) (2017-02): "SmartM2M Smart Appliances SAREF extension investigation".</li>

  <li id="[i.2]">[i.2] ETSI TR 103 511 (V1.1.1) (2018-10): "SmartM2M; SAREF extension investigation; Requirements for AgriFood domain".</li>

  <li id="[i.3]">[i.3] ETSI TS 103 410-4 (V1.1.2) (2020-04): "SmartM2M; Extension to SAREF; Part 4: Smart Cities Domain".</li>

  <li id="[i.4]">[i.4] Verhoosel J. and Spek J.: "Applying Ontologies in the Dairy Farming Domain for Big Data Analysis". Proceedings of the 1st Semantic Web Technologies for the Internet of Things (SWIT) 2016 workshop, co-located with 15th International Semantic Web Conference (ISWC 2016), Kobe, Japan, October 2016, pg. 91-100, CEUR.

<br/>NOTE: Available at <a href="http://ceur-ws.org/Vol-1783/">http://ceur-ws.org/Vol-1783/</a>.</li>

  <li id="[i.1]">[i.1] ETSI TR 103 411: "SmartM2M Smart Appliances SAREF extension investigation".</li>

  <li id="[i.2]">[i.2] ETSI TR 103 511: "SmartM2M; SAREF extension investigation; Requirements for AgriFood domain".</li>

  <li id="[i.3]">[i.3] ETSI TS 103 410-4: "SmartM2M; Extension to SAREF; Part 4: Smart Cities Domain".</li>

  <li id="[i.4]">[i.4] Verhoosel J. and Spek J.: "<a href="http://ceur-ws.org/Vol-1783/">Applying Ontologies in the Dairy Farming Domain for Big Data Analysis</a>". Proceedings of the 1st Semantic Web Technologies for the Internet of Things (SWIT) 2016 workshop, co-located with 15th International Semantic Web Conference (ISWC 2016), Kobe, Japan, October 2016, pg. 91-100, CEUR.</li>

  <li id="[i.5]">[i.5] ETSI TS 103 781: "SmartM2M; Study for SAREF ontology patterns and usage guidelines".</li>

</ul>