Google scholar "sort by date" returns articles from last year only?
First, you should realize that Google Scholar is not the same thing as a "free" equivalent of a commercial scholarly database (e.g. EBSCO or ProQuest). Although it's great for finding grey literature and relatively obscure topics (not to mention tracking citation counts), it has some serious limitations for general literature reviews. In particular, it does not permit you to do many of the focused searches that commercial scholarly databases. I suspect that this is for copyright reasons, rather than technical reasons--the journal publishers probably wouldn't permit Google to search their copyrighted articles in depth without paying for it.

What this means for your purposes is that, in general, you cannot do a title-abstract-keyword search on Google Scholar. The exception is that you can search for abstracts only, but only for articles added to Google Scholar in the last year. That's what you get when you click on "Sort by Date"--it's not obvious, but that means "Sort articles added in the last year by date". This is only useful to find what's new, but is useless for any general search on what exists in the literature.

The solution is to search in a commercial scholarly database (e.g. EBSCO or ProQuest). Your library pays them for the right to access them, they pay the journals, and so the journals authorize this kind of search.