There are both universal and subject-specific encyclopaedias.
AU/AUL has access to many encyclopaedias, either printed or electronic, so search in the library database for an encyclopaedia covering your subject area.
For example, go to 'Advanced search' and type 'Encyclopaedia' followed by your subject in the title field (remember truncation characters), filter for 'books' - note that you will also be searching in chapter titles.
Handbooks, which are ‘edited’ anthologies where different specialists within the field write about their particular area of expertise, are often good sources. Please note that a book may well have 'Handbook' in the title without being an anthology. Search the library database for handbooks within your subject.