Resources for topos theory I am trying to learn topos theory and I am finding a strong scarcity of resources. Is there any canonical textbook to refer someone to when learning this topic?
So far, I have only been able to find the following.

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*The Stacks project (Part 1, Chapter 7 gives an introduction)

*"Théorie des Topos et Cohomologie Etale des Schémas" by Grothendieck, Artin and Verdier (yes, this one is quite old and in French but I have found all the necessary topics together in a better way than any other resource known to me)

In particular, I have only found a clear distinction between topology and pretopology in the second one, as well as clear guidance on how to work interchangeably between them.
Do people have any suggestions? Please list them below so other people trying to learn topos theory have a better idea of where to start!
 A: Here are some references on Steven Vickers works to look at topoi from other "geometric" and logical sides.

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*S. Vickers,    Locales and Toposes as Spaces Chapter 8 in  M. Aiello, I. Pratt-Hartmann and J. van Benthem (eds.), Handbook of Spatial Logics, 429–496. 2007 Springer,

*S. Vickers,    Toposes pour les vraiment nuls

*S. Vickers,    Sketches for arithmetic universes

*S. Vickers,    Arithmetic universes and classifying toposes
I think it also worth to mention the following

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*I. Moerdijk,  Classifying Spaces and Classifying Topoi (surprisingly to me this one is available online as well)

For some advanced matters I also suggest to read

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*T. Streicher,  Fibered Categories
A: For a beginner, the more accessible textbooks seem to be the following two.

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*Francis Borceux, Handbook of Categorical Algebra, Volume 3.


*Saunders Mac Lane, Ieke Moerdijk: Sheaves in Geometry and Logic.
They both cover sheaves, Grothendieck topologies, locales, classifying toposes,
and other classical topics.
The second book is a bit longer and covers some additional topics,
e.g., the independence of the axiom of choice and continuum hypothesis.
A: Dmitri has mentioned two fantastic references, which are very complete and well written.
I will mention two short references for those that want to get the general idea, before approaching a complete book.

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*Leinster, An informal introduction to topos theory.

*Borceux, Some glances at topos theory.
