 Adams won the 1972 Carnegie Medal from the Library Association , recognising the year 's best children 's book by a British subject . He also won the annual Guardian Children 's Fiction Prize , a similar award that authors may not win twice . In 1977 California schoolchildren selected it for the inaugural California Young Reader Medal in the Young Adult category , which annually honours one book from the last four years . In The Big Read , a 2003 survey of the British public , it was voted the forty @-@ second greatest book of all time . 
