I worked as illustrator, cartoonist and writer for some magazines and books in Italy (on paper and on line), but I never signed any contract and I never received money. Some publisher asked to me to send inedited works only, for the publication, and to put a link to their magazines while using my works elsewhere. This request was made by email.
Now I stopped working since more than a year, and another italian publisher made me an offer, that's to say re-using my old works for collecting them on a website, on some e-books, for some products which will give me some profit, so he asked to me the permission of keeping my comics and illustrations from my personal blog for such purpose.
My doubt is-> since my personal blog does contain works which have been published on the magazines and books I mentioned, I wonder if I should worry about the copyright: am I supposed to ask the permission to the previous publishers before using them for other porpuses, both personal and commercial?
In other words: since I never signed any contract, am I the copyright owner of all my works?
(If I don't, may my works be re-published by mentioning the previous medias, at least?)