I know this was an old request, and I know that Penny S was looking for a book of carols and not this sheet music of two carols, but there is some useful librarian-type info in this entry:

Title Two folk carols ... ... : S.A.T.B. (unacc.) /? arranged by Malcolm Sargent.
Also Titled
       Star in the South
       Zither carol
Other Creators Herbert, A. P. (Alan Patrick), 1890-1971.
       Sargent, Malcolm, 1895-1967.
Published London : Oxford University Press, c1958.
Medium [music]
Content Types notated music
Carrier Types volume
Physical Description 1 score (5 p.) ; 26 cm.
Series The Oxford choral songs
Subjects Herbert, A. P. (Alan Patrick), Sir, 1890-1971 -- Musical settings.
       Carols, English -- Poland.
       Carols, English -- Czechoslovakia.
       Choruses, Sacred (Mixed voices, 4 parts), Unaccompanied.
       Carols, English.
       Czechoslovakia.
       Poland.
Contents
       Star in the South (Polish folk tune) /? words by A.P. Herbert
       Zither carol (Czech folk tune) /? words by Malcolm Sargent.
Music Publisher No. X 50
Libraries Australia ID 3779342
Contributed by Libraries Australia


Links for the entries which come up for The Oxford choral songs series, "Published London : Oxford University Press ; Sydney : Boosey &? Hawkes, [190-?]":

Unison &? two-part choral songs

The Oxford choral songs

And a YouTube video:
Star in the South (arr. Malcolm Sargent) ? Elora Festival Singers