In The Winston Grammar Program learning is incremental, with each lesson building upon previously-learned material. All lessons after the first, therefore, contain some built-in review. Most lessons introduce a new concept stated as a focus in the following (30 worksheet in the contents) list; however, some lessons are entirely review work. For a free catalog, phone (800) 348-1750 or Hewitt Educational Resources, PO Box 9, Washougal, WA 98671. (from book)