1 “...Pure and applied mathematics : a series of monographs and textbooks...”

2 “...Pure and applied mathematics, a series of monographs and textbooks...”

3 “...Pure and applied mathematics; a series of monographs and textbooks...”

4 “...Pure and applied mathematics, a series of monographs and textbooks...”

5 “...Pure and applied mathematics a series of monographs and textbooks...”

6 “...Pure and applied mathematics; a series of monographs and textbooks...”

7 “...Pure and applied mathematics, a series of monographs and textbooks...”

8 “...Pure and applied mathematics : a series of monographs and textbooks...”

9 “...Pure and applied mathematics; a series of monographs and textbooks...”

10 “...Pure and applied mathematics; a series of monographs and textbooks...”

11 “...Pure and applied mathematics; a series of monographs and textbooks...”

12 “...Pure and applied mathematics, a series of monographs and textbooks...”

13 “...Pure and applied mathematics; a series of monographs and textbooks...”

14 “...Pure and applied mathematics, a series of monographs and textbooks...”

15 “...Pure and applied mathematics, a series of monographs and textbooks...”

16 “...Pure and applied mathematics; a series of monographs and textbooks...”

17 “...Pure and applied mathematics; a series of monographs and textbooks...”

18 “...Pure and applied mathematics a series of monographs and textbooks...”

19 “...Pure and applied mathematics, a series of monographs and textbooks...”

20 “...Pure and applied mathematics, a series of monographs and textbooks...”