United States. War Department, Dictionary of Spoken Russian — §5… (1945)
“ If the stress of a set of forms is on the endings, then in a form which has no ending the stress is on the last vowel of the stem: карандаш [k'randaš] "pencil," with no ending, belongs to the set карандаши [k'r'ndaši] "pencils," карандашей [k'r'ndašey] "of pencils," and so on. The last vowel may be an inserted vowel: отец [atjec] "father" belongs to the set отцы [atci] "fathers," отцов [atcof] "of fathers," and so on. Quite a few words, however, have shifting stress, now on one syllable, now on another: голове [g'lava] "head," but головы [gol'vi] "heads." ”
