7. Benjamin Warren. The Diagonal Intersection Lies on the Radical Line of Two Certain Circles in a Quadrilateral, pp. 26-29..pdf
6. Benjamin Warren. More on the Circles Which are Centered at Vertices of a Triangle and Passing Through the Rest of the Vertices, pp. 23-25..pdf
5. Benjamin Warren. The Midpoints of the Vertices and the Midpoints Between the Vertices and the Circumcenter Lie on the Same Conic, pp. 20-22..pdf
4. Benjamin Warren. On a Certain Permutation Ellipse, pp. 16-19..pdf
3. Benjamin Warren. The Midpoint of the Midpoints of the Diagonals of a Quadrilateral, pp. 12-15..pdf
2. Benjamin Warren. The Ellipses that Pass Through a Triangle Vertex Whose Foci are the Other Two Vertices, pp. 9-11..pdf
1. Samuel Porritt. On a pair of twin conics, pp. 1-8..pdf
Volume 9.1.pdf