1. Hereditarily-pythagorean fields and orderings of higher level;Becker;Lecture Notes, No. 29,1978
2. Quadratic Forms, Orderings and Abstract Witt Rings;Bos,1984
3. Superpythagorean fields;Brown;J. Algebra,1976
4. An approximation theorem for extended prime spots;Brown;Canad. J. Math.,1972
5. Ordered fields satisfying Rolle's theorem;Brown;Illinois J. Math.,1986