Book endnotes and footnotes:
- Book endnotes: to add a note at the end of a book you need to click on "Notes" in the lower left part of the side navigation bar, enter the text of the note in the editor, and then return to the book by clicking on "Book" in the top left part of the side navigation bar. Now select the part of the text you would like to link to the note you just included, click on "internal links" in the top part of the menu. In the window that opens, click on Notes and select the reference note;
- Footnotes: to add a footnote click on  in the top part of the menu, write the text of the note, select the part of text or the text point you want to link to the note, click on "internal links" in the top part of the menu, select Footnotes and select the reference note.
The footnotes are indicated with small numbers, while the book endnotes are not.