Walker, E., & Elsworth, S. (1994). Grammar practice for intermediate students: With answer key. Burnt Mill: Longman.
Παραπομπή Chicago StyleWalker, E., και S. Elsworth. Grammar Practice for Intermediate Students: With Answer Key. Burnt Mill: Longman, 1994.
Παραπομπή MLAWalker, E., και S. Elsworth. Grammar Practice for Intermediate Students: With Answer Key. Burnt Mill: Longman, 1994.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.