ACM Digital Library

• Many of the items in ACM Digital Library are included as full text or are accessible from the database (such as videos). To access the text, you can click on the eReader or PDF icons. These can be accessed on either the results list or in the item record. 
• If you are searching the ACM Full Text collection, all items have the full text included. Items from the ACM Guide to Computing Literature, however, do not all have the full text included in ACM Digital Library and only the publication details such as author, title and publication title etc are available, as well as information about the article such as citation information, though this is typically not as extensive as for items where the full text is included.
• If you find an item where the full text is not available, then check UCL Explore to see if we have access to that item via one of our subscriptions. We have made a video that shows how to check, or you can look at our UCL Explore guide for more details.
• Many papers include a DOI link, which you can click on to see if it is a freely available open access article, (or if you are on campus or using the UCL VPN you may be able to access it via UCL's subscriptions without logging in). However, we would recommend always checking UCL Explore if you can't access it that way as we may have access to it via a route other than the publisher's website.
• If UCL does not provide access to it, then you can request an interlibrary loan, suggest a purchase or contact your subject librarian to see if there is another way of accessing the item. 

A Digital Object Identifier (or DOI) is a permanent, stable link to a specific item online. It is more stable than a URL, as URLs can change, for example if an organisation re-structures its website. You might see the DOI in a reference list or bibliography, as it is a reliable way to locate articles online.