diff --git a/html/src/front.md b/html/src/front.md
index a9e8bcb..438be5d 100644
--- a/html/src/front.md
+++ b/html/src/front.md
@@ -12,13 +12,15 @@ I have scaled down some of these materials to eBook size, for easier reading on
-
Homotopy Type Theory Book
- [[cached](https://git.mzhang.io/school/type-theory/raw/branch/master/resources/HoTT.pdf)]
- [[live](https://hott.github.io/book/hott-ebook.pdf.html)]
+ [[ebook-sized pdf](https://hott.github.io/book/hott-ebook.pdf.html)]
-
On the Formalization of Higher Inductive Types and Synthetic Homotopy Theory, by Floris van Doorn (2018)
- [[ebook](https://git.mzhang.io/school/type-theory/raw/branch/master/resources/VanDoornDissertation/dissertation.pdf)]
- [[original](https://florisvandoorn.com/papers/dissertation.pdf)]
+ [[ebook-sized pdf](https://git.mzhang.io/school/type-theory/raw/branch/master/resources/VanDoornDissertation/dissertation.pdf)]
+ [[original pdf](https://florisvandoorn.com/papers/dissertation.pdf)]
-
A Concise Course in Algebraic Topology, by J.P. May (2007)
- [[ebook](https://git.mzhang.io/school/type-theory/src/branch/master/resources/MayConcise/ConciseRevised.pdf)]
- [[original](https://www.math.uchicago.edu/~may/CONCISE/ConciseRevised.pdf)]
+ [[ebook-sized pdf](https://git.mzhang.io/school/type-theory/src/branch/master/resources/MayConcise/ConciseRevised.pdf)]
+ [[original pdf](https://www.math.uchicago.edu/~may/CONCISE/ConciseRevised.pdf)]
+-
+ [[ebook-sized pdf](https://git.mzhang.io/school/type-theory/raw/branch/master/resources/CCHM/main.pdf)]
+ [[original pdf](https://arxiv.org/pdf/1611.02108)]