Experienced collectors of art, as well as amateur art enthusiasts from all over the world are visting Berko's galleries. They regularly participate in the most prestigious art fairs, including those of Brussels, Paris, Maastricht, Palm Beach, Monaco, London and Shanghai. They have published a number of art books and dictionaries including the 'Berko', 'Dictionary of Belgian Painters born between 1750 and 1875', 'Dictionary of Belgian and Dutch Flower Painters born between 1750 and 1880' and the 'Dictionary of Belgian and Dutch Animal Painters born between 1750 and 1880'. The Berkos also have written numerous monographs including 'Fernand Toussaint', 'Georges Lemmers', 'Paul Mathieu', 'Paul Leduc', 'Caroline Stienon du Pré' and 'Georges Rogy'.