What’s the difference between L-citrulline and citrulline malate?

L-citrulline is often combined with malate, an intermediary of the Krebs cycle. In theory, supplementing with malate could increase ATP production, potentiating L-citrulline's ergogenic effects.^[1] Although there has been some promising research showing that citrulline malate can improve exercise performance^[2], it’s unclear whether citrulline malate is superior to citrulline, as there is currently no research directly comparing the two.