http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
"The last of a series of four novels ... The book was planned, without being in an sense a sequel, as part of a picture which includes three other sections.--'The green bay tree.' 'Possession,' and 'Early autumn.' Taken together the four might be considered as a single novel with the ... title 'Escape.'"--Foreword.