1. [1] E. Bombieri and L. Simon, On the Gehring link problem, (to appear).
2. [2] C. Croke, private communication, 1980.
3. [3] M. Edelstein and B. Schwarz, On the length of linked curves, Israel J. Math. 23 (1976), no. 1, 94–95.
4. [4] H. Federer, Geometric measure theory, Die Grundlehren der mathematischen Wissenschaften, Band 153, Springer-Verlag New York Inc., New York, 1969.
5. [5] T. Figiel, J. Lindenstrauss, and V. D. Milman, The dimension of almost spherical sections of convex bodies, Acta Math. 139 (1977), no. 1-2, 53–94.