Added some References

README.md

@@ -1,3 +1,8 @@
 # LPIC-1_101-400
 
-My slides fot my LPI 101 classes.
+My slides for my LPI 101 classes.
+
+References:
+-------
+* https://www.lpi.org/our-certifications/exam-101-objectives
+* https://www.tuxcademy.org/download/en/grd1/grd1-en-manual.pdf