Book publishers have been vocal about the sales of adult coloring books in the last few months, declaring this to be a global best-seller. While the hobby continues to be a favorite pastime, there's another childhood activity geared for grown-ups that could give rise to book sales too.

On sites like Amazon, dot-to-dot activity books for adults fill the inventory with tons of selections. Just like coloring, it's supposed to help you relax and temporarily take your mind of the stressful stuff in your life.

"The effect of the dot-to-dot is the same as the coloring-in - it helps take your mind away from your busy lifestyle and it's an easy way to relax and remove yourself for a little while," said Emily Wallis a dot-to-dot book illustrator from London, via Daily Mail. Wallis' book, the "Anti-Stress Dot-to-Dot," contains 43 illustrations of nature, buildings, animals and people. The numbered drawings have an average of 400 dots, with each taking 15 minutes to complete.

Graphic designer Thomas Pavitte also created a dot-to-dot book for adults. His "1000 Dot-to-Dot" is released as a series. Some of his detailed drawings take the afternoon to finish and one of his challenging masterpiece is a 6,239 dot reconstruction of the Mona Lisa, per Metro.

"it's a great way to kill time on a trip or just to chill out and relax at home," said one review of Pavitte's book on Amazon. Some suggest the books to be great gifts for the holidays, but others claim that the numbers are too small and too detailed that it could cause eyestrain.

Yet, like adult coloring books, dot-to-dot books are drawing grown-ups in and those who have tried it sometimes color the drawings, combining two childhood activities.

Take a look at some of the works shared in Instagram:

Distraindo #dottodot #ligueospontos #cities #bdaygift

A photo posted by Ana Caroline M. Carneiro (@mezomoana) on Nov 30, 2015 at 5:23am PST

Completed this dot to dot, there were 1000 numbers..... #toomuchtimeonmyhands #shouldbeworking #audreyhepburn #audrey #dottodot A photo posted by Samanthajasmine92 (@samanthajasmine92) on Nov 29, 2015 at 9:54am PST