Perfect was released on September 13, 2011, and is a companion novel to Impulse.

A companion novel to the game is expected.

A companion novel, Palace of Mirrors, was released in 2008.

Midnight Sun was to be a companion novel to the series.

This book is a "companion novel" and not a part of the story told in the seven-book series.

Two series of companion novels were issued by the publishers.

In 2009-10, the school received $1,200 for audio books and the companion novels.

Rabkin is also an author, writing a number of companion novels for the Psych television series.

A companion novel with the same name, also written by John Jackson Miller.

The companion novel was a big hit, rising high on several bestseller lists.