In some cases, the tenses of the Perfect Continuous group are replaced by the correspondent tenses of the Perfect group. This replacement is:
With verbs that are not used in Continuous tenses.
They have been married for two years.
Они женаты уже два года.
In the Passive voice to avoid too long verbal forms.
This question has been discussed for two hours.
Этот вопрос обсуждают уже два часа.
Not obligatory but wishful in negative sentences.
I haven't read any English books for several months.
Я не читал ни одной книги на английском уже несколько месяцев.
Not obligatory with so-called non-terminative verbs - to live, to work, to study, to learn.
I've been living in this city all my life. = I've been lived in this city all my life.
Я живу в этом городе всю мою жизнь.