Providing on-line non-downloadable software for accessing a searchable database of a registry of digital reference citation links for scholarly and research materials via computer networks and the internet; providing metadata and customized data feeds comprised of user-defined information about authors, titles, digital object identifiers, licensing, funding and other information in relation to scholarly research via computer networks and the internet; providing network-based infrastructure to facilitate computer to computer access to a registry of unique identifiers and associated metadata that can be used to define relationships between digital objects that enable services to make scholarly research publications and content easy to find, link, cite, assess and reuse; providing on-line non-downloadable software, to define relationships between digital objects that enable services to make scholarly research publications and content easy to find, link, cite, assess and reuse; computer services, namely, creating computer network-based indexes of information and metadata together with related resources