The at-will practice is typically traced to a treatise published by Horace Gray Wood in 1877, called "Master and Servant". Wood cited four U.S. cases as authority for his rule that when a hiring was indefinite, the burden of proof was on the servant to prove that an indefinite employment term was for one year. In "Toussaint v. Blue Cross & Blue Shield of Michigan", the Court noted that "Wood's rule was quickly cited as authority for another proposition." Wood, however, misinterpreted two of the cases which in fact showed that in Massachusetts and Michigan, at least, the rule was that employees should have notice before dismissal according to the periods of their contract.