Horizon Information Portal

	Series	Count
1.	Opposing viewpoints series (Unnumbered)	300
2.	See Also American history series (San Diego, Calif.)	15
3.	Opposites	0
4.	See Doudna, Kelly, 1963- Opposites	6
5.	Opposites (Minneapolis, Minn.)	0
6.	See Donner, Erica. Opposites	6
7.	Oppositions books	1
8.	Oprah Winfrey Network documentary club	0
9.	See OWN documentary club	1
10.	Oprah's book club	15
11.	[Oprah's book club]	6
12.	Oprah's book club (Random House Large Print)	1
13.	Optical engineering (Marcel Dekker, Inc.) ;	2
14.	Optical illusions (Quarto Library (Firm))	0
15.	See Sarcone, Gianni A. Optical illusions	4