A method for enabling automated content aggregation based on deep Web sources, comprising: analyzing a plurality of deep web sources to detect a plurality of fields; selecting at least one field; and aggregating content provided to a plurality of deep web sources through said at least one field. The combinations of possible constrained structures and methods of fabrication are described. Moreover, the door opening may be increased by increasing the height of the roof. Thus, a peel-off phenomenon at the edge portions of the trench is prevented.