Census of England and Wales for the year 1861 ...
Presented to both houses of Parliament by command of Her Majesty.
APA Citation
Great Britain. Census Office. (1862). Census of England and Wales for the year 1861 ... London.
MLA Citation
Great Britain. Census Office. Census of England And Wales for the Year 1861 ... London, 1862.
Warning: These citations may not always be complete (especially for serials).