1. Sums of the inverses of binomial coefficients;Rockett;Fib. Quart.,1981
2. Sums of reciprocals of the central binomial coefficients;Sprugnoli;Integers,2006
3. Combinatorial Identities;Gould,1972
4. Om summasjon av potenser av binomial koeffisienten;Staver;Nor. Mat. Tidsskr.,1947
5. The sum of inverses of binomial coefficients revisited;Pla;Fib. Quart.,1997