The National Readership Surveys are conducted quarterly either by the British Market Research Bureau or by Research Services Ltd. (1956 - 1959 Research Services Ltd; 1960 - 1967 British Market Research Bureau; 1968 - 1973 Research Services Ltd; 1974 - 1976 British Market Research Bureau; from 1977 onwards Research Services Ltd.). These surveys are designed principally to provide detailed information about the newspaper and magazine reading habits of the British people. The sponsors are virtually all the leading newspaper proprietors and advertising agencies in the country; many leading manufacturers were also consulted over the plan of the surveys. All surveys are substantially the same in form and content. Further details are available from the Archive upon application.