Footnotes are indicated by superscript numbers in the text. They may be placed at the foot of each page or at the end of each chapter. Footnotes at the bottom of the page may be numbered either beginning with 1 on each page or consecutively throughout a chapter. When footnotes are used, the bibliography includes all references cited in the notes (and additional sources) and is arranged alphabetically. Footnotes may be typed in a smaller size than the text or in the same size; they are usually single-spaced with a double space between notes.