Sabbatarians, Sabbatarianism 
Defines Sabbatarianism as a rigorist conflation of the Christian Sunday with the Jewish Sabbath, devotes attention to Seventh-Day Sabbatarianism as well.
http://www.newadvent.org/cathen/13287a.htmSabbatarians 
Historical information on Sabbatarianism, in particular, the English Sabbatarians of the sixteenth and seventeenth centuries.
http://www.exlibris.org/nonconform/engdis/sabbatarians.html
Sabbath Observance 
1923 article from an Ontario newspaper about the hubbub caused by a suggestion to allow children to use a municipal swimming pool during a heat wave.
http://www.aloha.net/~mikesch/c-record.htm
The Bible Sabbath Association 
Non-denominational organization to promote fellowship and cooperation between Seventh-Day Sabbath keepers. Sells the Directory of Sabbath-Observing Groups. Includes articles.
http://www.biblesabbath.org/
Mid-South Sabbatarians 
Established to promote greater awareness of, and fellowship between, sabbatarians of various stripes, and to promote the biblical seventh day Sabbath.
http://members.aol.com/ITH521/local.html
Assorted Flavors of 7th day Sabbatarians 
Church links, ministries, fellowships and resources.
http://www.geocities.com/assorted_flavors_7thday/
Sabbatarianism 
Definition of the term. Distinguishes between strict or literal sabbatarianism, which can only apply to the seventh-day sabbath, and semisabbatarianism, which transfers the demands of the sabbath to Sunday.
http://mb-soft.com/believe/text/sabbatar.htm
Sabbatarianism Re-Examined 
Robert Brinsmead explores the fallacies behind sabbatarianism in a landmark 1981 paper.
http://www.quango.net/brinsmead/Sabbatarian.htm
A Digest of the Sabbath Question 
Outline of Robert Brinsmead's "Sabbatarianism Re-Examined."
http://www.quango.net/brinsmead/sabbathdigest.htm
Calvin in the Hands of the Philistines, or, Did Calvin Bowl on the Sabbath? 
Seeks to illuminate Calvin's actual teaching on Sabbath observance and recreation by unraveling the origins of an anecdote about John Knox supposedly finding Calvin bowling on the Lord's Day.
http://www.fpcr.org/blue_banner_articles/calvin_bowls.htm