Beat eggs until light. Gradually add sugar and anise extract. Beat 15 minutes, or until mixture is like soft meringue. Sift soda with flour; add slowly to egg-sugar mixture and add anise seed. Cover and let rest for 15 minutes. Roll 1/3 of the dough on a lightly floured surface to 1/4 inch thick. Flour wooden cookie presses or rolling pin and press on dough for a clear design. Cut apart into squares or rectangles (approximately 2 x 2 inches or 2 x 3 inches). Sprinkle extra anise seed on ungreased cookie sheet. Place squares/rectangles on cookie sheet and let stand overnight, approximately 12 hours. Bake for 20 minutes at 300°. Store in an airtight container.