UAP Canada is the distributor for Nortrace 10-16-38. You may want to contact them for a local source.
I'm curious as to its use too; hopefully the OP will shed some light on it. Plumerias, bananas, and adeniums were mentioned in online discussions but not to a great extent. There was this posting that suggested 20-20-20 is not a balanced fertilizer and that 10-16-38 would be a better alternative. It would be great if a fertilizer expert would elucidate on this point.