Requirements for keywords selection
Keywords are certain words from the text capable of representing the most significant words by which the article can be evaluated and searched. Therefore, should reflect the discipline (the field of science, within the framework of which the article is written), the theme, purpose and object of research.
Single words, as well as word combinations in the singular and nominative case, can be used as keywords. The recommended number of keywords is 5–7 in Russian and English, the number of words inside the key phrase is no more than three. Main principles of keyword selection are:
use basic terms;
do not use words that are too complex;
each keyword is an independent element.