1. Hereditarily Pythagorean fields and orderings of higher level;Becker,1978
2. Summenn-ter Potenzen in Ko¨rpern;Becker;J. Reine Angew. Math.,1979
3. Valuations and real places in the theory of formally real fields;Becker,1982
4. Diagonal forms of higher degree;Becker;J. Reine Angew. Math.,1980
5. On the real spectrum of a ring and its applications to semialgebraic geometry;Becker;Bull. AMS,1986