This is the 7247th most frequent Polish word.
jonesa
The word "jonesa" does not exist in Polish. It might be a misspelling or mistaken term.
Here, 'Jonesa' is the genitive form used to indicate possession.
Jestem fanem gry Jonesa.
I am a fan of Jones's game.
In this case, 'Jonesa' shows the author of the book, again utilizing the genitive case.
Książka napisana przez Jonesa jest wspaniała.
The book written by Jones is wonderful.
Here, 'Jonesa' is in the accusative case to denote the direct object of the verb 'znam' (I know).