Search any Warframe item
Melee Prowess: Drop sources, locations, and probabilities
Mobs Dropping Melee Prowess
Melee Prowess can be dropped by most ennemies in Warframe. You should probably consider this as your primary farm source.
Other items:
Melee Guidance - Melee Doughty - Melee Duplicate
Melee Fortification - Melee Retaliation - Melee Vortex
Melee Guidance - Melee Doughty - Melee Duplicate
Melee Fortification - Melee Retaliation - Melee Vortex