diff --git a/codes/classical/properties/block/distributed_storage/info_retrieval/pir.yml b/codes/classical/properties/block/distributed_storage/info_retrieval/pir.yml
index 420ee4794..7c7c4f640 100644
--- a/codes/classical/properties/block/distributed_storage/info_retrieval/pir.yml
+++ b/codes/classical/properties/block/distributed_storage/info_retrieval/pir.yml
@@ -7,7 +7,7 @@ code_id: pir
 
 name: 'Private information retrieval (PIR) code'
 short_name: 'PIR'
-introduced: '\cite{doi:10.1145/293347.293350,doi:10.5555/795662.796270}'
+introduced: '\cite{doi:10.1145/293347.293350,doi:10.1109/SFCS.1995.492461}'
 
 description: |
   A code used to obtain information from several servers privately, i.e., without the servers knowing what information was obtained.
@@ -15,7 +15,7 @@ description: |
   A \(k\)\textit{-server PIR code} is a block code for which one can recover any coordinate of a codeword from \(k\) disjoint sets of coordinates of the codeword \cite{arxiv:1505.06241}.
 
 notes:
-  - 'See Ref. \cite{doi:10.1017/9781009283403,doi:10.5555/795662.796270}.'
+  - 'See Ref. \cite{doi:10.1017/9781009283403,doi:10.1109/SFCS.1995.492461}.'
 
 relations:
   parents: