A fact from 2012 Swiss referendums appeared on Wikipedia's Main Page in the Did you know column on 3 May 2012 (check views). The text of the entry was as follows:
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The first link you provide is not the OED - it is a company trading on a similar name, possibly to make people think they are the OED. As for the third link which you are using to justify your stance, you have conveniently omitted its final sentence: "So – ‘referendums’ or ‘referenda’? As it turns out, it’s all really just a matter of preference." Although there are no doubt a few exceptions to the rule, Wikipedia has always used referendums. I myself originally used referenda on here until it was pointed out to me by another editor that it was incorrect. Number5708:53, 20 March 2012 (UTC)Reply
I mentioned the usage of rferendums too. But you were correct...even the WP article doesnt differentiate or point to referendums(Lihaas (talk) 10:24, 1 May 2012 (UTC)).Reply
I have now moved it to "referendums" on the basis that there are numerous ones to be held on different dates during the year. Number5717:05, 14 June 2012 (UTC)Reply