Each compendium in the Echelon Reference Series: Spells line contains the compiled spell list and all spells on that spell list. For instance, the Echelon Reference Series: Magus Spells Compiled has all seven levels (including cantrips) of magus spells. The spell lists are broken down by level and spell school — while most classes don’t have mechanical distinctions based on school, it helps provide some thematic differentiation in the list. The spells themselves are grouped by level and then ordered by name.
The compilations have also been split up into single-level PDFs, for those who need only a subset of the spells. For instance, Echelon Reference Series: Sorcerer/Wizard Spells is somewhat more than 1,100 pages; if someone is playing a third-level wizard they can buy just the spell levels they would use. Because of how bundling works at DriveThruRPG, if someone buys some of the level-specific PDFs, the price of those PDFs is removed from the cost of the bundle, and I include the compilation in the bundle for free — I don’t charge for it separately, you get it free if you’ve already bought the other PDFs in the bundle.
