Are California voters about to impose world’s first ‘tax on billionaires’? BBCThe millions spent by California billionaires against Prop. 40 is about 0.07% of their wealth Los Angeles TimesCalifornia’s Prop 40: What to know about the billionaire wealth tax Yahoo FinanceDave Regan Pushed the Billionaire Tax Hard. Now He Faces a Union Inquiry. The New York TimesOpinion | Why the fate of California’s wealth tax could be decided well after the election CalMatters