many columns with references to one table

Hi,

What is the problem with the following table declaration?

CREATE TABLE persons (
id SERIAL PRIMARY KEY,
name TEXT NOT NULL,
bdate DATE,
address INTEGER REFERENCES addresses,
phonepriv INTEGER REFERENCES phones,
phoneday INTEGER REFERENCES phones,
phonemobil INTEGER REFERENCES phones,
email INTEGER REFERENCES emails,
mate INTEGER REFERENCES persons,
updated DATE NOT NULL
);

My problem is that the references to the phones table do not get
restricted, i.e. I can insert any value in the phone*-fields, while the
references to the other tables are restricted to values that allready
exists. The table declaration of phones should be all right, it has a
primary key defined like every other tables I have. Is there a
restriciton that no more then 1 column may reference an other table?

Regards

Andreas Fromm