Eckstut-Didier, Samuela. Focus on Grammar. A Basic Course For Reference And Practice / Work Book Samuela Eckstut - 2nd ed. - London : Longman , 1994 . Includes index. ISBN: 0201656833 LCCN: 99053402 Subjects--Topical Terms: English language--Grammar LC Class. No.: PE1128 Dewey Class. No.: 428.2/4