Your sources are both right, but about different types of public records.
There are three kinds of public records that may appear on your credit report: tax liens, financial judgments, and bankruptcies.
Unpaid tax liens can remain for 15 years. Your second source is right that paid tax liens will remain for seven years from the paid date, even though it may mean the item remains for longer than 15 years total.
Financial judgments – if you are sued and lose, for example – remain for seven years from the filing date. Your first source was correct in that regard.
Bankruptcies can remain either seven years from the filing date for completed Chapter 13, or 10 years from the filing date for Chapter 7.
Experian removes Chapter 13 sooner because it includes at least partial repayment of the debt. Chapter seven remains longer because it does not include any debt repayment.
Thanks for asking.