What are the names of the stations which serve both "Ananthapuri Express" and "Guruvayur Express" train?
SELECT T2.name FROM train_station AS T1 JOIN station AS T2 ON T1.station_id   =   T2.station_id JOIN train AS T3 ON T3.train_id   =   T1.train_id WHERE T3.Name   =   "Ananthapuri Express" INTERSECT SELECT T2.name FROM train_station AS T1 JOIN station AS T2 ON T1.station_id   =   T2.station_id JOIN train AS T3 ON T3.train_id   =   T1.train_id WHERE T3.Name   =   "Guruvayur Express"
stations which serve both 'Ananthapuri Express' and 'Guruvayur Express' refers to using INTERSECT to find common stations; names of the stations refers to SELECT station_name;