Please give the additional contact information of the oldest employee with the jod position of sales person.
Sales person refers to PersonType = 'SP'; oldest employee refers to Max (Subtract((now())-BirthDate));
SELECT T2.AdditionalContactInfo FROM Employee AS T1 INNER JOIN Person AS T2 ON T1.BusinessEntityID = T2.BusinessEntityID WHERE PersonType = 'SP' ORDER BY T1.BirthDate ASC LIMIT 1