diff --git a/pages/audio.metadata.md b/pages/audio.metadata.md
index 7a4c86c..f139f86 100644
--- a/pages/audio.metadata.md
+++ b/pages/audio.metadata.md
@@ -19,6 +19,7 @@
 - bwf - https://en.wikipedia.org/wiki/Broadcast_Wave_Format 
 	- *this seems to be liked by profesionals*
 		- https://mediaarea.net/BWFMetaEdit/xml_chunks
+		- https://www2.archivists.org/sites/all/files/Andrec,%20Michael.pdf fulltext? where?
 - XMP - https://en.wikipedia.org/wiki/Extensible_Metadata_Platform
 - dolby - https://professionalsupport.dolby.com/s/topic/0TO4u000000f1pFGAQ/audio-metadata?language=en_US
 	- probably interesting just for dolby