Here are some notes (in Spanish) I wrote while I was working on my Bachelor's and Master's theses. The notes are not comprehensively reviewed, so they may contain some mistakes and typos. 

Introducción a las Integrales Singulares.

Teoría de Pesos en Análisis Armónico.

I would like to thank my Bachelor's and Master's advisor, María Jesús Carro Rossell, for her patience, guidance, and motivation during the studying of the topics presented.