If youre a mockup sharing website like mockupworld you MUST link back to the original page. If youre a user using my mockups for work, school projects, ads, product showcase, etc you DO NOT need to link back.
All resources available for download on my portfolio are free to use in both personal and commercial projects.
You are permitted to use my resources in any number of personal or commercial projects for yourself or a client. You may modify the resources according to your requirements and include them into works such as websites, applications, printed materials and others. A link back to my portfolio site is optional but for mockup sharing websites a Link back is required.
You do not have the rights to resell, sublicense or redistribute (even for free) the files on its own or as a separate attachment from any of your work. If you wish to promote my resources on your site, you must link back to the resource page where users can find the download and not directly to the download file.