select (a.surname||' '||a.lastname||' '||a.patronymic) as fio
from abonents a, tariff_plan t, subscriber_base s, personal_account p
where a.id_abonent = s.abonent_id and t.id_tariff = s.tariff_id and p.contract_id = s.id_contract and t.id_tariff = 4
and (p.date_entry Between current_date - 30 AND current_date)
Group by fio