Where's Enhanced Summoning from?

[Epametheus]

I saw Pax mention it in the thread on summons that he mentioned, and I know I've seen it before, but I can't seem to find it now. What book is it from?

For that matter, is it a feat, or an Alienist class ability?

 

[Vlos]

Couple of sources I believe.

Alienest (ToB)

Feat: Augement Summon (source?)

Unearth Arcana (has rules for ehanced summon - I believe)

 

[Ogrork the Mighty]

Thaumaturgist from Complete Divine?