Wikipedia says that the Sveshnikov Variation is :
[FEN ""]
1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5
While chesstempo says that is the Lasker-Pelikan Variation, and the Sveshnikov is strictly :
[FEN ""]
1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 d6 7.Bg5 a6 8.Na3 b5.
There is no central authority for opening names, and the ones used shift over time. So a definite answer to this question isn't possible.
Bad_Bishop quotes Silman's review of "Sicilian Sveshnikov: Move by Move", which is a bit odd as the book itself treats all variations after 5...e5 (see the PDF preview of the book, chapter "Sixth Move Alternatives".
The same is true of "The Sicilian Sveshnikov" by Kotronias (PDF preview).
But these are repertoire books for black; if you play 5...e5 and white wants to, he can basically force 6.Ndb5 d6 7.Bg5 a6 8.Na3 b5 as there are few serious alternatives for black. So if you play the Lasker/Pelikan, you play the Sveshnikov too, and vice versa. It's logical that they want to treat white's alternatives at move 6 too, so that the book is more widely useful. But then, why not call it "The Lasker/Pelikan: Move by Move"?
I think the name "Lasker/Pelikan" is obsolete, at least in English language chess publications. I've never seen it used in any book or periodical or website in at least twenty years, it's always Sveshnikov. You can easily find many books on the Sveshnikov, and I don't know any on the Lasker/Pelikan. Apart from that Silman review, but he has played chess for a long time.
ECO (and thus the Informant) calls it the Lasker/Pelikan, but its codes and their names are set in stone since the 1960s. Those codes and their names have also ended up in many computer files of opening names, but as far as I can see it's not actually used by anybody anymore.
It's just the Sveshnikov.
RemcoGerlich's answer is excellent: the Lasker-Pelikan and the Svechnikov are basically the same variation; it is defined by 5...e5 but the line until 8...b5 is the main continuation afterwards and the resulting position where White can choose between 9.Bxf6 and 9.Nd5 can be considered as its real tabyia. The name "Lasker-Pelikan" is outdated, almost obsolete, and nowadays "Svechnikov" is the way to call that variation.
To complement the historical evolution, the variation was known as the "Lasker-Pelikan", or just the "Pelikan" until the beginning of the 70's, when it was considered dubious and was not popular at all. Then youngsters like Svechnikov, Timoshchenko and Vladimirov gave the line a boost, but because they were no famous grandmasters (yet!) but just some obscure teenagers, Russian theoreticians named the line from the city they were coming from, Tcheliabinsk - for about 10 years 5...e5 became "the Tcheliabinsk variation" (or even sometimes "the Tcheliabinsk-Novossibirsk variation" !).
In the eighties, Svechnikov became a strong grandmaster, kept being successful with his pet line and wrote a good reference book about it, so more and more people referred to the line as "the Svechnikov Sicilian" and that is the standard name ever since. Yakovich's, Rogozenko's, Kotronias' and Lakdawala's books about the variation all have the name "Svechnikov" in their titles.
Evgenny Svechnikov's own book about the line is actually entitled "The Sicilian Pelikan". I think it was published in 1986 or 1987 in the USSR, what is sure is that the English translation went out in 1989. This title is a display of modesty by the author, since the names "Svechnikov", "Svechnikov-Vladimirov", and "Tcheliabinsk" were already much more in vogue than "Pelikan" in the eighties.
Addendum Jan,2,2019:
Another early expert from the city of Chelyabinsk who contributed a lot to the develoment of this opening, Gennady Timoshchenko, just published his own book about the variation, entitled "Sicilian Defence - the Chelyabinsk Variation".
Its "Part I The History of the Variation and Its Development" includes a chapter "About the Name of the Variation" that would be very interesting in regard to this question. Especially if we consider the author's contempt for Svechnikov's analyses !
This is IM Silman's review of Sicilian Sveshnikov: Move by Move, the emphasis is mine:
Cyrus Lakdawala’s latest book for Everyman also uses the Move by Move format, engaging the reader with a question and answer format that should make the Sveshnikov (1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 d6 7.Bg5 a6 8.Na3 b5) accessible to a much wider audience that previous works on the subject.
So the longer line is the Sveshnikov. The other lines are sub-variations, often with their own names.
I wouldn't get too caught up about naming conventions. To quote Bruce Pandolfini in the Chessmaster academy:
But this is chess, that is names.
