Family search - free on-line genealogy search site has many census records online.
https://familysearch.org/
You can search - and cut and paste the details to your tree for references. You should always include the familysearch source (copy the URL that is in the address bar). Below is an example of their standard format) Some census years have more data - such as birth month and year, years married, number of children/living children; birthplace of parents etc. than other census years.
https://familysearch.org/pal:/MM9.1.1/MN1D-YBP
United States Census, 1920
Name: Harvey M Hudson
Residence: , Grady, Oklahoma
Estimated Birth Year: 1842
Age: 78
Birthplace: Missouri
Relationship to Head of Household: Father
Gender: Male
Race: White
Marital Status: Widowed
Father's Birthplace: Tennessee
Mother's Birthplace: Tennessee
Film Number: 1821462
Digital Folder Number: 4384003
Image Number: 00102
Sheet Number: 6
Household Gender Age Birthplace
SELF Edward A Hudson M 42y Missouri
WIFE Johnnie K Hudson F 37y Arkansas
DAU Ida E Hudson F 17y Oklahoma
SON Oscar H Hudson M 14y Oklahoma
SON Orvil Hudson M 10y Oklahoma
SON Edward R Hudson M 6y Oklahoma
SON Emmet W Hudson M 3y Oklahoma
FATH Harvey M Hudson M 78y Missouri