Havel, Vâaclav. The increased difficulty of concentration [[Book] /] translated from the Czech by Vera Blackwell. - London : Cape, 1972. - 78 p. ; 19 cm. - Cape editions, 49 . Translation of Ztâiézenâa moéznost soustéredéenâi. Play. Bibliography: p. 76. ISBN: 0224618601 022461861X (pbk.) : 022461861X (pbk.) 022461861X (pbk) 9780224618601 9780224618618 (pbk.) LCCN: 72189389 //r83 LC Class. No.: PG5039.18.A9 / Z4513 Dewey Class. No.: 891.8625 891.8625 891.8625 National Library of Medicine Call No.: / H I