Copyrights must be respected, and the author and (original) source of cited material (including the photographer) must always be mentioned. Protected material may also be used free of charge and without separate permission in an academic non-commercial text within the framework of the right of quotation: e.g. a suitable, published excerpt of music (not too long and not too short), an image published by a museum or otherwise found on the Internet, a translated poem, if these are discussed in the text (i.e. they are appropriately connected to the work of the citing person). This means that the example is “incorporated in the text”; in other words, images used for the sake of their own may not be used without compensation. In principle, citations must always mention all author and publisher information unless it proves impossible to find them.
An exception from this is, for instance, material from museums and archives that is held by the museum and that the author has gained access to by signing an access agreement with the museum: such material may not be used without permission and compensation. On the other hand, images available on the Internet, e.g. ones published on museum websites may typically be used within the framework of the right of quotation. The cited image must have been made legally available to the public: it is published e.g. by the museum itself and is not a pirated version.
The sources and/or copyright holders of figures and other references can also be included in a separate list and not in the captions. This is typically done in the case of images.
More information is available on the Art Universities Copyright Advice and The Uniarts Helsinki Publication Guide.