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\begin{center}
{\Large \textbf{Tµi liÖu tham kh¶o}}
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\renewcommand{\refname}{\normalsize \textbf{TiÕng ViÖt}}

\begin{thebibliography}{20}

\bibitem{fer} D­¬ng Minh §øc (2000), \emph{Gi¶i tÝch hµm}, NXB §¹i häc Quèc gia TP.HCM.

\bibitem{fer} NguyÔn Xu©n Liªm (1994), \emph{§é ®o vµ tÝch ph©n}, NXB Gi¸o dôc.

\bibitem{fer} NguyÔn §×nh Ph­ (2002), \emph{Ph­¬ng tr×nh vi ph©n}, NXB §¹i häc Quèc gia TP.HCM.

\end{thebibliography}

\renewcommand{\refname}{\normalsize \textbf{TiÕng Anh}}

\begin{thebibliography}{20}

\bibitem{fer} Jerzy Zabczyk (1992), \emph{Mathematical Control Theory An Introduction}, Birkhaeuser.

\bibitem{fer} L.S. Pontriagin (1962), \emph{Ordinary Differential Equation}, Addison-Wesley, Mass.

\bibitem{fer} Serge Lang (1969), \emph{Analysis II}, Addison-Wesley, Reading Massachusetts, USA. 

\end{thebibliography}

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