On the search page, you can use "Подключение БПА " function to select databases you want to search. If you want to search by date, be careful that there's a bug with the "Дата подписания" search function, as you can not choose a year earlier than 1972, but the databases actually have documents dating to 1917. As a solution, you may select an end date and sort the search results in ascending order.
