I hope all is well. So, here is the issue with the question that you asked... The books that are currently out there are 1. not that great, and 2. not going to get better before the end of 2018 (this is important for the following reason)…
Microsoft is changing the exam and entire structure of the Azure Learning path as of January 1, 2019.
IF... you are planning on certifying PRIOR to the end of 2018, then your best bet is the following book:
I would supplement this with the materials that I have pointed out and provided through the show, and you should be fine. Take a look at the 70-535 show notes download package as well, as there are some additional docs that will be helpful.
IF you are planning on waiting to take the exam until sometime after January 1, 2019, then take a look at the following:
I would wait to see what books are published towards end of 2018, into early q1 of 2019 to address the new certs and learning paths.
We will be reshooting and updating the current Azure content to reflect the shift and re-orientation going into Q1 of 2019.
Hope that helps. :)
Good Luck !!