388 REFERENCES TO THE LITERATURE 



Thus far the statements apply to the literature which follows 

 and which is arranged alphabetically by authors' names and under 

 authors, by date. 



2. Subject references. It was desirable at the same time to 

 present some sort of a subject classification, and this has been done 

 in the following manner. 



At the end of each chapter, references to the literature bearing 

 on the subject of the chapter are given by author's name and date. 

 The full reference appears in the list at the end of the volume. 

 The chapter lists contain not only the citations in the text, but 

 also other references which have not been cited there. The 

 presentation is not uniform but dictated by the arrangement of 

 the chapter. Where possible, the references are given in alphabet- 

 ical order without subdivisons, but where it will be of advantage 

 to have the references grouped according to the sub-headings, 

 this is done, although under this plan the same reference may 

 appear under more than one sub-heading. 



