iBooks 
Add special characters, symbols, and mathematical symbols
Use the Characters window to insert special characters, such as mathematical symbols, letters with accent marks, arrows, and dingbats.
Note: Emoji (smiley face) characters are not supported.
Insert a special character or symbol
Place the insertion point where you want the special character or symbol to appear.
Choose Edit > Special Characters.
In the Characters window, select a category from the list on the left, and double-click a character to insert it.
For more information about the Characters window, click your desktop and choose Help > Help Center.