Depending on the country the artwork was created determines its copyright length. So you will have to try and find what country published the book.
And make the assumption that the artwork was created in 1971.
And assuming it is US:
pma = post mortem auctoris, (years) after the death of the author
p.d. = post divulgationem, (years) after publication
p.r. = post realisation, (years) after creation
ibid. = ibidem, “in the same place”
70 pma (works published since 1978)
95 p.d. or 120 p.r. whichever is shorter (anonymous works, pseudonymous works, or works made for hire, published since 1978)
95 p.d. for works published 1964-1977; 28 (if copyright not renewed) or 95 p.d. for works published 1923-1963 (Copyrights prior to 1923 have expired.)
Rule of the shorter term: No