I am using sectsty package in my document, that is http://tex.stackexchange.com/questions/107281/centering-chapter-section-subsection (last one answer (modification)), and when I say chapterfont{\centering}
\sectionfont{\centering}
\subsectionfont{\centering}, chapters, ..., subsections are centered, but for some reason content and reference are also centered, and I don't know why