- IndCat: IndCat is a free online Union Catalogue of Books, Theses and Serials of major university/institute libraries in India. The IndCat contains bibliographic information, location and holdings of Books, Theses and Serials
https://indcat.inflibnet.ac.in/index.php/main/
- Library Hub Discover: Library Hub Discover makes rare and unique research materials easier to find by bringing together the catalogues of major UK and Irish libraries. With a single search, you can find out what the UK's National Libraries, including the British Library, many university libraries, and specialist research libraries
https://discover.libraryhub.jisc.ac.uk/
- NUCSSI: National Union Catalogue of Scientific Serials in India (NUCSSI) is the properly maintained union catalogue of the scientific serials in India which is made available in digital form through web user interface. This data repository serves as an appropriate tool to access Journal holdings information. It is established and maintained by INSDOC which is officially recognised as NIScPR.
http://nucssi.niscair.res.in/
- SUNCAT: The Serials Union Catalogue, abbreviated as SUNCAT, is the national union catalogue of the serials in UK which later became significant at international level. It is created in 2003 under Research Support Libraries Programme (RSLP).
https://suncat.stanford.edu/
- Trove : Trove, owned by the National Library of Australia, is an online library database with partnerships with source providers National and State Libraries Australia, an aggregator and service that includes full-text documents, digital images, bibliographic and holdings data of non-digital items, and a free faceted-search engine for discovery
https://trove.nla.gov.au
- WorldCat: The WorldCat is the world's largest network of library content and services. WorldCat libraries are dedicated to providing access to their resources on the Web, where most people start their search for information
https://www.worldcat.org/
