The dificulty with the engines are there robots: most of them are controlled by Google. You can try brave, presearch, startpage, yandex, duckduck, bing, yahoo et cetera; It comes to narrowing the results. And in early days - before google - there was Northenlight, that was a very good search-engine. Today the engines work with a algorithm that puts the most profitable sites on top; they say there are x milion results, but when you click further, they stop at page 53 or less.
You are screwed when trying to deep search!