Obscure Venn diagram references

• Obituary of John Venn, Proceedings of the Royal Society London, A 110 (1926) x-xi.
• Robert Froman, A Young Math Book: Venn Diagrams, Fitzhenry and Whiteside, 1972. [A book for young children about the uses of Venn diagrams. At most 3 sets are used.]
• Ted W. Yellman, Better than Venn? -- The Ben Diagram, IEEE Trans. Reliability, 38 (1989) 341-342. [The "Ben" is for Ben Franklin]