[1] Courant, R.: 
Differential and integral calculus, Volume 1.  2nd English edition, Blackie, 1937. 
MR 1009558[4] Monteiro, G. A., Slavík, A., Tvrdý, M.: 
Kurzweil-Stieltjes integral. Theory and applications.  World Scientific, 2019. 
MR 3839599[5] Nelsen, R.: 
Proofs without words. Exercises in visual thinking.  Mathematical Association of America, 1993. 
MR 1573050[6] Nelsen, R.: 
Proofs without words II. More exercises in visual thinking.  Mathematical Association of America, 2000. 
MR 1573580[7] Netuka, I.: Integrální počet. Vícerozměrný Lebesgueův integrál.  MatfyzPress, 2016.
[10] Veselý, J.: Základy matematické analýzy, díl druhý.  MatfyzPress, 2009.
[11] Young, W. H.: On classes of summable functions and their Fourier series.  Proc. R. Soc. Lond. Ser. A 87 (1912), 225–229.