Marker David, Introduction to the model theory of fields. Model theory of fields, Lecture notes in logic, no. 5, Springer, Berlin, Heidelberg, New York, etc., 1996, pp. 1–37.Marker David. Model theory of differential fields. Model theory of fields, Lecture notes in logic, no. 5, Springer, Berlin, Heidelberg, New York, etc., 1996, pp. 38–113.Pillay Anand. Differential algebraic groups and the number of countable differentially closed fields. Model theory of fields, Lecture notes in logic, no. 5, Springer, Berlin, Heidelberg, New York, etc., 1996, pp. 114–134.Messmer Margit. Some model theory of separably closed fields. Model theory of fields, Lecture notes in logic, no. 5, Springer, Berlin, Heidelberg, New York, etc., 1996, pp. 135–152.