The international version of Yandex, the Russian search engine, has a collection of advanced commands that include a proximity operator that is extremely useful for drilling down to what your really want. For example, a search statement might be, “opec & saudi” (in same sentence) or “opec && saudi” (in same page).
There is also an /n operator that enables you to specify that words or phrases must appear within a certain distance of each other. For example, a search statment might be “opec saudi /3”
An interesting operator is the non-ranking “and”, which is entered as “<<“: the words after the operator do not affect the ranking of the page in the results.
The search operators are listed at https://yandex.com/support/search/how-to-search/search-operators.xml.