The Contents are placed after the Introductory.

The numbers in the right margin refer the page numbers of the original printed book, they appear just where the corresponding page begins, e.g., the original page 113 contains the text between the labels “p. 113” and “p. 114” in this version.

Changes to the original publication (possible typographic errors or inconsistencies) have been marked with a dotted underline, and the printed text usually appears in a “pop-up box” when hovering the cursor on it.