What is the burden of proof against a defendant who is not a resident of the forum state?

"When jurisdiction is challenged by a nonresident defendant, the burden of proof is upon the plaintiff to demonstrate that 'minimum contacts' exist between defendant and the forum state to justify imposition of personal jurisdiction." (Mihlon v. Superior Court (1985) 169 Cal.App.3d 703, 710, 215 Cal.Rptr. 442.) "The plaintiff has the right to conduct discovery with regard to the issue of jurisdiction to develop the facts necessary to sustain this burden." (Ibid.)