References. List references in consecutive numerical order (not alphabetically). All subsequent reference citations should be to the original number. Cite all references in the text or tables. Unpublished data and personal communications should not be listed as references. References to journal articles should include (1) author(s) (list all authors and/or editors up to 6; if more than 6, list first 3 and “et al”), (2) title, (3) journal name (as abbreviated in Index Medicus), (4) year, (5) volume number, and (6) inclusive page numbers, in that order. References to books should include (1) author(s) (list all authors and/or editors up to 6; if more than 6, list first 3 and “et al”), (2) chapter title (if any), (3) editor (if any), (4) title of book, (5) city of publication, (6) publisher, and (7) year. Volume and edition numbers, specific pages, and name of translator should be included when appropriate. The reference numbers in the reference list (if any) should be keystroked. Do not let the word-processing program generate the reference numbers, using such features as automatic footnotes or endnotes. The author is responsible for the accuracy and completeness of the references and for their correct text citation. Do not include “personal communications” in the list of references. Authors who name an individual as a source for information in a personal communication, be it through conversation, a letter, e-mail message, or telephone call, should obtain written permission from the named individual.