diff --git a/frontend/static/languages/polish_10k.json b/frontend/static/languages/polish_10k.json
index ceaaacc01..86bddfca0 100644
--- a/frontend/static/languages/polish_10k.json
+++ b/frontend/static/languages/polish_10k.json
@@ -1,6 +1,7 @@
 {
   "name": "polish_10k",
   "leftToRight": true,
+  "_comment": "Based on 'Otwarty słownik frekwencyjny leksemów V.06.2009' by Jerzy Kazojć. Retrieved November 02, 2022 from https://web.archive.org/web/20091116122442/http://www.open-dictionaries.com/slownikfrleks.pdf",
   "bcp47": "pl-PL",
   "words": [
     "a",
@@ -10004,4 +10005,4 @@
     "żądza",
     "żądło"
   ]
-}
\ No newline at end of file
+}
diff --git a/frontend/static/languages/polish_20k.json b/frontend/static/languages/polish_20k.json
index 69dd8c761..ac7e52203 100644
--- a/frontend/static/languages/polish_20k.json
+++ b/frontend/static/languages/polish_20k.json
@@ -1,6 +1,7 @@
 {
   "name": "polish_20k",
   "leftToRight": true,
+  "_comment": "Based on 'Otwarty słownik frekwencyjny leksemów V.06.2009' by Jerzy Kazojć. Retrieved November 02, 2022 from https://web.archive.org/web/20091116122442/http://www.open-dictionaries.com/slownikfrleks.pdf",
   "bcp47": "pl-PL",
   "words": [
     "a",
@@ -20004,4 +20005,4 @@
     "żłobek",
     "żłób"
   ]
-}
\ No newline at end of file
+}
diff --git a/frontend/static/languages/polish_40k.json b/frontend/static/languages/polish_40k.json
index 1f08fce38..824f8e288 100644
--- a/frontend/static/languages/polish_40k.json
+++ b/frontend/static/languages/polish_40k.json
@@ -1,6 +1,7 @@
 {
   "name": "polish_40k",
   "leftToRight": true,
+  "_comment": "Based on 'Otwarty słownik frekwencyjny leksemów V.06.2009' by Jerzy Kazojć. Retrieved November 02, 2022 from https://web.archive.org/web/20091116122442/http://www.open-dictionaries.com/slownikfrleks.pdf",
   "bcp47": "pl-PL",
   "words": [
     "a",
@@ -40004,4 +40005,4 @@
     "żłób",
     "żłóbek"
   ]
-}
\ No newline at end of file
+}
diff --git a/frontend/static/languages/polish_5k.json b/frontend/static/languages/polish_5k.json
index 3fbc8f413..59b7a9064 100644
--- a/frontend/static/languages/polish_5k.json
+++ b/frontend/static/languages/polish_5k.json
@@ -1,6 +1,7 @@
 {
   "name": "polish_5k",
   "leftToRight": true,
+  "_comment": "Based on 'Otwarty słownik frekwencyjny leksemów V.06.2009' by Jerzy Kazojć. Retrieved November 02, 2022 from https://web.archive.org/web/20091116122442/http://www.open-dictionaries.com/slownikfrleks.pdf",
   "bcp47": "pl-PL",
   "words": [
     "a",
@@ -5004,4 +5005,4 @@
     "żądać",
     "żądza"
   ]
-}
\ No newline at end of file
+}