1. D. Borkin and R. Lipton, A lower bound of 1/2 n2 on the knapsack problem, in preparation.
2. On the complexity of computations under varying sets of primitive operations;Dobkin,1975
3. Proving simultaneous positivity of linear forms;Rabin;J. Comput. System Sci.,1972
4. V. Strassen, personal communication, May 1975.