What does it mean if the Library Catalogue says Journals for the location?
All journals are shelved at shelfmarks which begin PER followed by a two-digit is a number which corresponds to the broad subject area e.g. PER 68 for Electrical Engineering journals. You can find journals on the relevant subject floors: they are shelved alphabetically by title, within the numerical subject sequence. So you will find the European Journal of Organic Chemistry, PER 54, on Level 4, which is the subject floor for Chemistry. Full listing of of journal shelfmarks with corresponding levels of the Library.