a) Leaving out the year of publishing
If it is not possible to include the year of publishing in the list of references, as is often the case with electronic sources, one can leave out the year of publishing both in the in-text references and the list of references.
b) Electronic articles with no permanent link
In some cases, an electronic article does not have a permanent online address or link. With these kinds of sources, the Internet address where the article is available is marked according to the Internet address of the service.
c) Electronic publication with no author