Sourcebooks, in a sizeable deal for its trade division, has acquired the 1-2-3 Magic parenting series. The 13-book line has sold more than 1.6 million copies worldwide, and has been translated into 22 languages.

The series, developed by Chicago area clinical psychologist Thomas W. Phelan, focuses on discipline techniques with an emphasis on curbing bad behavior and strengthening the relationship between parents and children.

The deal goes into effect January 1, and in February Sourcebooks will reissue the sixth edition in the series, 1-2-3 Magic: Effective Discipline for Children 2–12, which was first published in 1995. Sourcebooks will also release new editions of other works by Phelan: 1-2-3 Magic in the Classroom (spring 2016), Surviving Your Adolescents (fall 2016) and All About ADHD (spring 2017).

Sourcebooks v-p and editorial director, Todd Stocke, said the deal was “a huge add for the Sourcebooks adult nonfiction list.” He also noted that the publisher is particularly excited about "the opportunity to actually increase Dr. Phelan's sales, build his brand, and expand his impact on families.”

Stocke called the acquisition both a “traditional publishing deal” and a “very creative partnership.” Aside from reissuing Phelan’s books, Sourcebooks will work with him to develop new releases, assume management of the 1-2-3 Magic website, and implement marketing strategies to grow sales.

The financial terms of the acquisition were not disclosed, but Sourcebooks described them as “significant.”