Laws of the Game 2017-18 + 2018-19 Updates
This is a pdf file issued by The International Football Association Board.
Clicking on the above links will open the file in your pdf reader.
You are welcome to read it online or download it but, be warned, it is 212 pages.
A very interesting and useful publication.
Changes to Laws of the Game 2017/18.
If you do not have Adobe Reader or similar installed, download it here.