Andreu-Vaillo F., Mazón J. M., Rossi J. D., Toledo-Melero J. J., Nonlocal Diffusion Problems, American Mathematical Society, Providence, Rhode Island 2010.

	Kamont Z., Ordinary Differential Equations, Wydawnictwo Uniwersytetu Gdanskiego, Gdansk 1999 [in Polish].

	Muszynski J., Myszkis A. D., Ordinary Differential Equations, Panstwowe Wydawnictwo Naukowe, Warszawa 1984 [in Polish].

	Pelczar A., Szarski J., Introduction to the Theory of Differential Equations, Panstwowe Wydawnictwo Naukowe, Warszawa 1987 [in Polish].