PostgreSQL: Introduction and Concepts by Bruce Momjian - Mailing list pgsql-general

i was doing a search on foreign keys and found this link from your web
page: http://www.postgresql.org/docs/aw_pgsql_book/29061.html

and reading through the book was really helpful. i'm wondering why such
marterial isn't listed on:

http://www.postgresql.org/docs/