diff --git a/documents/references.md b/documents/references.md
index 773e042f5041acf1e428c1351fa5d23c0cc91b05..7c9c0509ad9cda91716e63cddce0b24f4ffcf9ae 100644
--- a/documents/references.md
+++ b/documents/references.md
@@ -43,8 +43,12 @@ Scipy is a scientific library that seems to now be generally associated with Num
 <https://jakevdp.github.io/PythonDataScienceHandbook/02.04-computation-on-arrays-aggregates.html>
 
 #### Finding the Range of Data
-Looks like this isn't built into scipy/numpy. Have to create it ourselves, which isn't difficult.
+Looks like this isn't built into scipy/numpy. Have to create it ourselves, which isn't difficult.<br>
 <https://stackoverflow.com/a/12701694>
 
+### Finding Quartiles of Data
+Looks like this isn't built into scipy/numpy. Have to create it ourselves, which isn't difficult.<br>
+<https://www.geeksforgeeks.org/interquartile-range-and-quartile-deviation-using-numpy-and-scipy/>
+
 #### Finding the Mode of Data
 <https://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.mode.html>