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The theory of the étale fundamental group of affdssf \cite[Proposition~5]{szamuely} schemes is  introduced in \cite[Proposition~5]{szamuely}.

The book \cite{knuth68} is still unfinished.

\cite{knuth68, szamuely}

\begin{thebibliography}{999}
	\bibitem{knuth68}
		Donald Knuth,
		\emph{The Art of Computer Programming},
		Volume I, Addison-Wesley, 1968.
	
	\bibitem{lang-algebra}
		Serge Lang,
		\emph{Algebra},
		Springer,
		2002.

	\bibitem{szamuely}
		Tamás Szamuely,
		\emph{Galois Groups and Fundamental Groups},
		Cambridge University Press,
		2009.
\end{thebibliography}

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