Frey, Hugo. History / Hugo Frey. - London : Teach Yourself Books, 2002. - viii, 104 pages. ; 20 cm. - 101 key ideas . ISBN: 0340845406 Nat. Bib. No.: GB A2-Z8739 Subjects--Topical Terms: History. LC Class. No.: D 20 / .F73 Dewey Class. No.: 909