Merge origin/master

specifications/README.md

@@ -8,6 +8,10 @@ space exploration and medicine.*
 * [Simulation Interoperabilty Standards Organization (SISO)](https://www.sisostds.org): "Simulation Interoperability and Reuse through Standards"
 * SISO Product Support Group (PSG): [DIS / RPR FOM PSG - Distributed Interactive Simulation / Real-time Platform Reference Federation Object Model](https://www.sisostds.org/StandardsActivities/SupportGroups/DISRPRFOMPSG.aspx)
 
+Resources from the working group:
+* [DIS PDU data structures](IeeeDisPduColorFigures.pdf)
+* [Compressed DIS](2019-SIW-Presentation-039_CompressedDis.pdf)
+
 Manual download links follow.  IEEE standards must be downloaded manually while within NPS campus or firewall.
 
 ## Standards Documents