On the Finnish version of a page for a release e.g. Laulaja, it will often say "Julkaisuvuosi: 1994", which is "Release date", in the top right. But on the English version of the same page this information is missing.
Linking to Aanitearkisto
If you search for anything in aanitearkisto, the search results will be listed on a page with the URL http://www.aanitearkisto.fi/firs2/en/haku.php .
It is no good using this URL as a source or external link because it will take you to an empty page. Haku means something like "search" or "search results", but the URL doesn't contain the search string. So, if you click on the link, Aanitearkisto will have no idea what you are searching for.
The solution is (with "Ding-a-dong" as an example):
Search for e.g. the work Ding-a-dong. This will take you to http://www.aanitearkisto.fi/firs2/en/haku.php
Click on any label (as they call it) (in this case of Marion Rung, Emi 5e 006 35079 ( 45 ) or on any album title
In the resulting page, click on Ding-a-dong once more. Now you are at http://www.aanitearkisto.fi/firs2/en/kappale.php?Id=Ding-a-dong and this is the link you need for the source or External Link.
More on step 2: If you click on what they call a label, you will go to a page precisely for the 45, cassette or lp. If you click on an album title, you will go to a page listing all the formats for that album (and any other album that happens to have the same title). Any of these will do as the source or External Link for the release.
Ding-a-dong also perhaps is an opportunity to say that if there are several recordings from the same year, you can't use Aanitearkisto to say which one is the original. Six artists recorded Ding-a-dong in 1975, one with a precise recording date, but unfortunately Aanitearkisto lists them in alphabetical order by artist name.