1. N. Bourbaki, Alg. Comm. VI, Section 3, No.1.
2. Non-Archimedean amoebas and tropical varieties;Einsiedler;J. Reine Angew. Math.,2006
3. Tropical algebraic geometry;Gathmann;Jahresber. Deutsch. Math.-Verein,2006
4. On valuation spectra;Huber;Contemp. Math.,1994
5. V-valuations of a commutative ring I;Harrison;J. Algebra,1989