1. Double tangency theorems for pairs of submanifolds;Banchoff;Geometry Symposium,1980
2. On the double tangents of plane closed curves;Fabricius-Bierre;Math. Scand.,1962
3. Global theorems for closed plane curves;Halpern;Bull. Am. Math. Soc.,1970
4. Planes triply tangent to curves with nonvanishing torsion;Freedman;Topology,1980
5. T. Banchoff, T. Gaffney and C. McCrory: Counting Tritangent Planes of Space Curves. To appear.