I have a book of quotations that displays a 1967 copyright. I would like to use some of them in a current work of mine that I intend to publish.
Many of the quotations in the 1967 book I can trace back to sources, the copyrights of which have expired. However, there are some I cannot—though the quotes themselves were uttered more than 95 years ago. Also, I am quite certain that their written sources (which I have not located) would have been published more than 95 years ago.
QUESTION: Legally, may I extract quotes from the copyrighted 1967 book and incorporate them into my book, which I intend to publish in the United States?