Punctuation in book's/ article's title

I just googled and found there is a book called "Less Is More, More Or Less."

May I ask for a book title, or if it is an article title, is the full stop at the end of the title necessary?

On the other hand, if it is natural to use a full stop at the end, is it also natural to use two full stops ─ like "Less Is More. More Or Less."?

source

Book titles do not normally take a period at the end. (Here is a site that lets you format titles by various style guides.)

Typically, a period used at the end of a sentence, after a book title in quotation marks, applies to the sentence itself, not to the book title.

If the display of italics is possible, this would often be the preferred way of indicating a book title—rather than quotation marks.

But in North America, commas and periods go inside final quotation marks. Unless you understand the rule, it can cause this kind of confusion.

However, in this particular case, it appears as if the author of the book, Nathan Brown, has deliberately broken with convention and put a period at the end of the title. I would have said it was just a graphical representation of the title being shown on the book cover, but an ISBN search actually shows the period in the title text itself.

So, no. It's not "natural" for book titles to include sentence-level punctuation. But it's not unheard of.

For example, a famous short story by Philip K. Dick, upon which the movie Blade Runner was based, is called Do Androids Dream of Electric Sheep? Note the question mark at the end. It's uncommon, but still possible. (Here is a list of book titles ending in a question mark.)

There are special rules for such book titles when it comes to things like citations. For example, many styles of citations indicate that you put a period after a book title in bibliographies and works-cited lists. But if the title ends in a question mark, you do not add a period.

This is the first time I can recall a book title that actually includes a period. (I may have seen one before but forgotten about it.)

Stylistically, my preference would be to phrase any sentence that includes such a title so that the title comes at the end—and that the period in the title acts to punctuate the sentence as well. Other representations, while technically correct, could look strange.

Note, too, that even if this book title did not include a period, the first sentence you gave in your question would still be written exactly the same way (if in North America and using quotation marks).