additional reading

Author: wprzytula

content/lessons/07_smart_pointers/index.md

@@ -63,6 +63,7 @@ Alongisde the `RefCell<T>` type described above, there is an analogous [`Cell<T>
 # Additional reading
 
 - [On wrapped references](https://www.fpcomplete.com/blog/rust-asref-asderef/)
+- [`Deref` vs `AsRef` vs `Borrow`](https://dev.to/zhanghandong/rust-concept-clarification-deref-vs-asref-vs-borrow-vs-cow-13g6)
 
 ## Assignment 5 (graded)