diff --git a/UCDlist.tex b/UCDlist.tex
index 6319f2f..0094d9c 100644
--- a/UCDlist.tex
+++ b/UCDlist.tex
@@ -115,7 +115,7 @@ \section{List of valid words}
 
 For typographic reasons some long UCD atoms are printed on two
 lines in the following table.  In these cases, \texttt{some.long...
-...ucd.x} is to be read as \texttt{some.log.ucd.x}.
+...ucd.x} is to be read as \texttt{some.long.ucd.x}.
 
 \newpage
 
@@ -772,7 +772,8 @@ \subsection{Goal}
 
 \subsection{Remarks on combination rules}
 The combination rules have been defined in the first IVOA documents defining UCD concept
-\citep{2005ivoa.spec.0819D}. They are exposed with a syntax tag given as a property of each UCD word 
+\citep{2005ivoa.spec.0819D} and refined in the last UCD1+ standard recommendation \citep{2018ivoa.spec.0527M}. 
+They are exposed with a syntax tag given as a property of each UCD word 
 and included in the list of UCD words. See Section \ref{sec:list} with the tags definitions on top.
 
 They correspond to real usage of the terms in science publications and are attached to the description 
diff --git a/localrefs.bib b/localrefs.bib
index 4e12f14..4da85a6 100644
--- a/localrefs.bib
+++ b/localrefs.bib
@@ -42,3 +42,26 @@ @misc{std:UCDMAINT-PR
         Url = {http://www.ivoa.net/documents/UCDlistMaintenance/},
         Year = {2019},
 }
+@MISC{2018ivoa.spec.0527M,
+       author = {{Martinez}, Andrea Preite and {Louys}, Mireille and {Cecconi}, Baptiste and {Derriere}, Sebastien and {Ochsenbein}, Fran{\c{c}}ois and {IVOA Semantic Working Group}},
+        title = "{The UCD1+ controlled vocabulary Version 1.3 Version 1.3}",
+ howpublished = {IVOA Recommendation 27 May 2018},
+         year = 2018,
+        month = may,
+        pages = {527},
+          doi = {10.5479/ADS/bib/2018ivoa.spec.0527M},
+       adsurl = {https://ui.adsabs.harvard.edu/abs/2018ivoa.spec.0527M},
+      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
+}
+
+@MISC{2019ivoa.spec.1007G,
+       author = {{Genova}, Fran{\c{c}}oise and {Louys}, Mireille and {Preite Martinez}, Andrea and {Cecconi}, Baptiste and {Derri{\`e}re}, Sebastien and {Molinaro}, Marco and {Delmotte}, Nausicaa and {Gray}, Norman and {Mann}, Robert and {McDowell}, Jonathan and {McGlynn}, Thomas and {Ochsenbein}, Fran{\c{c}}ois and {Osuna}, Pedro and {Rixon}, Guy and {Williams}, Roy and {IVOA Semantics Working Group}},
+        title = "{Maintenance of the list of UCD words Version 2.0 Version 2.0}",
+ howpublished = {IVOA Recommendation 07 October 2019},
+         year = 2019,
+        month = oct,
+        pages = {1007},
+       adsurl = {https://ui.adsabs.harvard.edu/abs/2019ivoa.spec.1007G},
+      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
+}
+