Simple and effective tools, they make it possible to reach quickly a great quantity of information. One finds there

• the catalogue of our library (with key words);
• the complete list of Paul Duvigneaud's publications;
• an inventory of bibliographical references concerning nature in the Brussels Capital Region: more than 900 references (at the beginning of a file established by Mr. Daniel Geerinck, which we thank);
• an inventory of publications devoted to urban ecology (Belgian and European cities, others that Brussels)