In this lightning talk, we will present ScholeXplorer and OpenCitations, two of the services included in the MONITOR portfolio of the OpenAIRE-Nexus project, a recently-funded H2020 project which aims at bringing in the EOSC several services provided by public institutions, e-infrastructures, and companies to implement and accelerate Open Science. In particular, ScholeXplorer and OpenCitations will feed the OpenAIRE Research Graph with billions of open data regarding bibliographic citations, and can be used to foster transparency and reproducibility of several activities (such as research results and assessment exercises) that were possible, in the past, only through the payment of a conspicuous fee to access proprietary services. ScholeXplorer and OpenCitations – and their tied relation with OpenAIRE, its Research Graph, and the EOSC – represent a new frontier of open citation indexing and can be used to enhance or develop new tools to support authors, researchers, bibliometricians, librarians, funders, academic administrators, research managers, data repositories, publishers, by providing, for example, metrics to monitor research at a given institution and by improving the discoverability of research products such as publications, data, and software.