Usually, a Digital Library (DL) is an information resource where users may submit queries to satisfy their daily information need. The CYCLADES system envisages a DL additionally as a personalized collaborative working and meeting space of people sharing common interests, where users (i) may organize the information space according to their own subjective view; (ii) may build communities, (iii) may become aware of each other, (iv) may exchange information and knowledge with other users, and (v) may get recommendations based on preference patterns of users. In this paper, we describe the CYCLADES system, show how users may define their own collections of records in terms of un-materialized views over the information space and how the system manages them. In particular, we show how the system automatically detects the archives where to search in, which are relevant to each user defined collection.