Wandering by late as usual to add that My Profession's Official Handbook (the MLA Handbook 9th edition) now (I swear it has changed I was first assigned it which must have been circa 1977 as an undergraduate) solemnly states that the possessive of all singular proper nouns ending with 's' will be made with the apostrophe+additional s. The possessive of plural proper nouns requires only the adopostrophe: "The Dickenses' economic woes" (2.51, p. 33). If you're interested, they have four rules for "singular and plural nouns" (2.51).
Thank you.
Wandering by late as usual to add that My Profession's Official Handbook (the MLA Handbook 9th edition) now (I swear it has changed I was first assigned it which must have been circa 1977 as an undergraduate) solemnly states that the possessive of all singular proper nouns ending with 's' will be made with the apostrophe+additional s. The possessive of plural proper nouns requires only the adopostrophe: "The Dickenses' economic woes" (2.51, p. 33). If you're interested, they have four rules for "singular and plural nouns" (2.51).