(a) To find where journals/newspapers are held within Cambridge
Holdings of the University Library, its dependant libraries and the faculty, departmental and college libraries are found in iDiscover
(b) To find where journals/newspapers are held outside of Cambridge
Library Hub Discover includes the holdings (serials, books and other materials) held in over 100 major libraries across the UK. (It absorbs, extends and replaces COPAC and SUNCAT which previously did this.)
The OCLC Union List of Periodicals will show you if a periodical is held in major research libraries throughout the world.
ZDF (Zeitschriften Daten Bank) is the union list of periodicals held in over 4,000 libraries in Germany.
You are reminded that articles from titles not held in Cambridge can very often be obtained for you on Interlibrary loan.