From publisher blurb:
Echelon Reference Series: Alchemist Extracts is a simple document that collects the alchemist extract list, and all extracts in it, for easy use. The extract lists are broken up by level and school, and the extracts of each level are grouped together and organized by name.
This is a subset of the entire book, containing only the 2nd-level alchemist extracts.
This is the 3pp+PRD version, containing information from the PRD and select third-party products.