Atlas of Human Anatomy by Netter

Medial wall of axilla
Receives lymph from breast, anterior thoracic wall
Subscapular group
Along posterior axillary fold
Receives lymph from posterior thoracic wall and scapula
Humeral (lateral) group
Along lateral wall of axilla
Receives lymph from upper limb
Central group
Deep to pectoralis minor
Receives lymph from pectoral, subscapular, and humeral groups