Add the record types of the POF - IBGE

Hello! I recently started messing with Stata. I need to analyze data from the POF - IBGE's Household Budget Survey. The 2008-2009 survey has 16 datasets, each referring to different aspects of the family (domicile, individual, expenses, income). There is no single variable to identify an observation in the datasets. Has anyone worked with this data and could you help me think of a way to merge the information I need into 3 of these 16 datasets (domicile, people, and income)? The only variables that are repeated in all datasets are 4 location variables - UF, sequence number (region), check digit of the sequential number and num of the sequential address. These four variables are like a filter until you get into the locals, but I do not know if it's possible with this to generate a householdid at least ... Thank you in advance.