diff --git a/radar-source.md b/radar-source.md
index e02d2f6..bd835dd 100644
--- a/radar-source.md
+++ b/radar-source.md
@@ -166,6 +166,7 @@ For data assets, the following properties are relavant in the context of CEOS-AR
 [CEOS Measurements Database]: <https://database.eohandbook.com/measurements/overview.aspx>
 
 [STAC]: <https://github.com/radiantearth/stac-spec>
+[Maturity Classification]: <https://github.com/radiantearth/stac-spec/tree/master/extensions/README.md#extension-maturity>
 
 [Authentication]: <https://github.com/stac-extensions/authentication>
 [CEOS-ARD]: <https://github.com/stac-extensions/ceos-ard>
diff --git a/radar.md b/radar.md
index a890936..b30a03e 100644
--- a/radar.md
+++ b/radar.md
@@ -153,24 +153,13 @@ The specification for STAC Items that cover the source data, please see the "CEO
 [CEOS-ARD product family specifications]: <http://ceos.org/ard/>
 [Combined CEOS-ARD for Synthetic Aperture Radar, version 1.0]: <https://ceos.org/ard/files/PFS/SAR/v1.0/CEOS-ARD_PFS_Synthetic_Aperture_Radar_v1.0.pdf>
 
-[CEOS Missions Database]: <https://database.eohandbook.com/database/missiontable.aspx>
-[CEOS Instruments Database]: <https://database.eohandbook.com/database/instrumenttable.aspx>
-[CEOS Measurements Database]: <https://database.eohandbook.com/measurements/overview.aspx>
-
 [STAC]: <https://github.com/radiantearth/stac-spec>
 [Maturity Classification]: <https://github.com/radiantearth/stac-spec/tree/master/extensions/README.md#extension-maturity>
-[Common metadata]: <https://github.com/radiantearth/stac-spec/tree/v1.0.0/item-spec/common-metadata.md>
-[Media Type]: <https://github.com/radiantearth/stac-spec/blob/master/item-spec/item-spec.md#asset-media-type>
 [Collection Summaries]: <https://github.com/radiantearth/stac-spec/tree/v1.0.0/collection-spec/collection-spec.md#collection-fields>
 [Collection Assets]: <https://github.com/radiantearth/stac-spec/tree/v1.0.0/collection-spec/collection-spec.md#assets>
 
-[Accuracy]: <https://github.com/stac-extensions/accuracy>
-[Authentication]: <https://github.com/stac-extensions/authentication>
-[Classification]: <https://github.com/stac-extensions/classification>
 [CEOS-ARD]: <https://github.com/stac-extensions/ceos-ard>
 [Processing]: <https://github.com/stac-extensions/processing>
 [Projection]: <https://github.com/stac-extensions/projection>
 [Raster]: <https://github.com/stac-extensions/raster>
 [SAR]: <https://github.com/stac-extensions/sar>
-
-[UDUNITS-2]: <https://ncics.org/portfolio/other-resources/udunits2/>