1. Über nicht-archimedisch geordnete Körper;Baer;Sitzungsber. Heidelberger Akad.,1927
2. Partial orders on a field and valuation rings;Becker;Comm. Algebra,1979
3. On orderings and valuations of fields;Dress;Geom. Dedicata,1977
4. Finite and infinite primes for rings and fields;Harrison;Mem. Amer. Math. Soc.,1966