diff --git a/ex4.md b/ex4.md
index a471ae1..fbbe70c 100644
--- a/ex4.md
+++ b/ex4.md
@@ -2,4 +2,18 @@
 
 2. Create a shared library of your code, which solved one of the Rosaild's problem
 
-3. Use any of the shared libraries of your chosen friend
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+3. Use any of the shared libraries of your chosen friend
+
+	https://github.com/MieszkoCharchuta/cpp_object
+
+	https://github.com/emilka-skrzypek/C-/blob/main/main.cpp
+
+	https://github.com/FrajarUAM/Obiektowe_Cpp/tree/b6829267807fb6e4a591c34fabb93d1c5c515fa0
+
+	https://github.com/Kamil-Patan/c--/tree/main/cpp%20obiektowe
+
+	https://github.com/Palmin00/programowaniecpp
+
+	https://gitea.com/emiliagnatiuk/programowanie-obiektowe.git
+
+	https://github.com/julpac5/julpac5
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