Yes, Ivan, " Paris's " and " Jones's " are right if we are to strictly follow the rule on the possessive case of singular nouns. However, it is not uncommon to see them also written as " Paris' " and " Jones' ", i.e., without the last "s". The last "s" is commonly removed when the word that follows also begins with the letter "s". For example, some may prefer to write "Mr. Jones's shoes are new" as "Mr. Jones' shoes are new" instead. Since the name of Marx does not end in "s", it will always be "Marx's" in its possessive form. Also, "Please explain me that:" should be "Please explain these to me:"

с неодушевлёнными " 's" не употребляется Mr.Jones's Marx's

You are correct... possessive pronouns (names) that end in "s" are this way.. Jones' (not Jones's) etc... Marx, however, does not end in an "s", so "Marx's" would be correct in that case.

Exactly!