As far as I'm aware, there are NO free software packages that can open .pub files, the only way you will be able to open them, apart from getting Microsoft Publisher, is to ask the author of the files to save them in a different format.
OnePlus 5T review: Hands-on
Illustrator Andrés Lozano on his improv line work, brazen use of colours & hand sketching
iPhone X review
Comment envoyer gratuitement des gros fichiers ?