Zhang X, Hasoksuz M, Spiro D, Halpin R, Wang S, Vlasova A, Janies D, Jones LR, Ghedin E, Saif LJ. Quasispecies of bovine enteric and respiratory coronaviruses based on complete genome sequences and genetic changes after tissue culture adaptation. Virology. 2007 Jun 20; 363(1):1-10.