diff --git a/README.md b/README.md
index 42482b2bbe73ea293996d8d570f4076ac6bf6018..e3a49d8f23eb2e89885f6ff2f6bdeb81c3d4e99c 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,11 @@ slice them and so on.
 Can be imported from _sai.series_. A generic abstract superclass for series - 
 `Series` can be imported for checking if given object is a series.
 
+Series are immutable, but non-hashable.
+
+Read the source code of the [base class](firanka/series/series.py#L11) to get
+to know more about series operations.
+
 ### DiscreteSeries
 
 To use a _DiscreteSeries_ you must give it a set of data to work with. These
@@ -115,6 +120,8 @@ Range's are immutable and hashable. They can be sliced:
 Range('<-5;5>')[0:] == Range('<0;5>')
 ```
 
+Slices work as a both-sides-closed range if both sides are shown!
+
 You can check whether a range contains a point
 
 ```python