create table cityperson
(
short_name      varchar2(3)  references city(short_name) on delete cascade,
contact_person  varchar2(60) not null,
ext_num		varchar2(6)  ,
city_phone	varchar2(10) ,
air_phone	varchar2(10) ,
fax_num     varchar2(10) ,
primary key(short_name,contact_person)
)
/