Then Brouwer's fixed-point theorem is one of the most celebrated theorems of analysis and topology that emerged in the first half of the twentieth century. Since the second half of the twentieth century various proofs of this theorem have arisen. Much of this proofs seeks simplicity and clarity. See for exemple
Studies notes by Professor RALPH HOWARD:THE MILNOR-ROGERS PROOF OF THE BROUWER FIXED POINT THEOREM.
In these excellent notes of Mathematical Analysis written by Professor Bruce Blackadar there exists in pages $1217$, $1218$ and $1219$ a proof scheme of Brouwer's fixed-point theorem. Although incomplete, they seem promising to me.
The proof scheme is basically the following: First, it is proved that the three theorems below are equivalent. Second, it proves that the last theorem is true.
Theorem. [ Brouwer Fixed-Point Theorem}] Every continuous function $f : B^n \to B^n$ has a fixed point, i.e. there is a point $x \in B^n$ with $f (x) = x$. \
Theorem. [No-Retraction Theorem] There is no retraction from $B^n$ to $S^{n-1}$ \
Theorem. [No-Contraction Theorem] The sphere $S^{n−1}$ is not contractible, i.e. the identity map on $S^{n−1}$ is not homotopic to a constant map.
And the point is precisely this, the proof scheme of Brouwer's fixed-point theorem seems to me to be incompletely written because it seems to me very simple or very short writing. See pages $1217$, $1218$ and $1219$ in Bruce Blackadar's notes.
My question is just this one. How to complete this idea of the proof of the fixed point theorem of Brouwer of rigorous way? Can this proof scheme be found in any reference other than Professor Bruce Blackadar's notes?