SELECT DISTINCT T1.name FROM nurse AS T1 JOIN on_call AS T2 ON T1.EmployeeID  =  T2.nurse
Find the names of nurses who are on call.
SELECT DISTINCT T1.name FROM nurse AS T1 JOIN on_call AS T2 ON T1.EmployeeID = T2.nurse
select distinct t1 . name from nurse as t1 join on_call as t2 on t1 . employeeid = t2 . nurse
Find the names of nurses who are on call .