Cream butter and sugar until light and fluffy. Stir in tangerine juice and peel. Add flour; mix well. Divide dough in half. Press each portion evenly into greased and flour 20 cm round cake pan. Decorate edges by crimping or pressing with tines of fork. Prick with fork to score top into pie-shaped wedges. Bake on center rack in preheated 325-degree oven 20 to 25 minutes, until shortbread is golden and edges are light brown. Remove from oven and cut into wedgesalong fork scored lines. Cool completely in pan. Makes 32 cookies. ----