Series — X

36 series

X Minus One (Black Eye Entertainment)

2 books

X Series

7 books

X-Calibur

1 book

X-Clan

4 books

X-Files (Maberry)

2 books

X-Men

5 books

X-Men and America Chavez Story

1 book

X-Men and Spiderman: Time's Arrow

4 books

X-Men and the Avengers: Gamma Quest Trilogy

4 books

X-Men: Mutant Empire

4 books

X-Ops

8 books

X-OPS: The Unclassified Files

1 book

X-Ray Visions

2 books

X-Treme American Dungeon League

4 books

X: The Beginning

1 book

X1cares

1 book

Xane Emotions

12 books

Xanth

6 books

Xantoverse

1 book

Xarc'n Warriors

7 books

Xavier

1 book

Xavier Bradshaw Crime Files

1 book

Xeelee Sequence

5 books

Xeno City Blues

2 books

Xeno Relations

2 books

Xenogenesis

3 books

Xenophobia Series

3 books

Xenotech Support

1 book

Xenowealth

4 books

Xerus Galaxy Saga

2 books

Xhoseti

2 books

Xi Force

4 books

Xian Warriors

11 books

Xiveri Mates

13 books

Xtinct!

2 books

Xuya Universe Romances

5 books