diff --git a/fin/blockchain/docs/books.txt b/fin/blockchain/docs/books.txt
new file mode 100644
index 000000000..fa883e8a0
--- /dev/null
+++ b/fin/blockchain/docs/books.txt
@@ -0,0 +1,8 @@
+2024
+AntonopoulosHarding - Mastering BTC 3rd ed ru
+    E7C9E3D1BBB38106FFB98EE4C0251FFE
+    88089895785EE9FC9F0A0CEFD574649B
+2023
+AntonopoulosHarding - Mastering BTC 3rd ed
+    89C551A4BE0DDE91D90110C199597E5C
+    C7112DA76B7AEB659E857DE8ABF22712
diff --git a/science/data-science/books.txt b/science/data-science/books.txt
new file mode 100644
index 000000000..c21a35a2e
--- /dev/null
+++ b/science/data-science/books.txt
@@ -0,0 +1,4 @@
+2025
+Nield - Essential Math for Data Science ru
+    694115682E6075A549F5D79E40F831D5
+    195481C58F72D785DF21B6AB2CD67DFB