How do I determine if investment income is from a NJ source

[HockeyDave]

I am filing a NJ non-resident form because I had some salary income from NJ for part of January 2016.  I also had dividend income from a Vanguard NJ Tax exempt fund.  Turbo tax is asking me how much of that dividend income is from NJ sources - the Fund is managed by vanguard, but the investment is in NJ government bonds.  The only thing I can see at the NJ state tax site talks about income derived from property or businesses in NJ.  Is the dividend income considered from a New Jersey Source?

[NancyG]

Not for your purposes.  If you opened a savings account while you were in New Jersey, the interest that account earned would be New Jersey source investment income.