I attempted to run a multilevel model with a nested sample (subordinates within leaders).

Variables are as follows:

(IV) Level 1 - leaders self-reported values

(IV) Level 1 - leaders self-reported Person-Organization Fit

(DV) Level 2 - subordinates ratings of leaders' ethical leadership behaviour

Sample size: 71 leaders matched with 220 subordinates

I am looking for references which may support why the models did not converge. I can no longer look at variation due to leaders, but only at the fixed effects.