Hello Rafael, I'm glad you find the pack interesting and that you want to use it in your game! :)
Here's the licensing to put in your credits :
Voxel Spaceships- Maxime Parata (maxparata.itch.io)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/
What is this game that you are making? any game page?