Nebulae
type: Concept
narrower: Dark interstellar clouds

Bok globules
type: Concept
broader: Dark interstellar clouds

Cometary globules
type: Concept
broader: Dark interstellar clouds

Dark interstellar clouds
type: Concept
alternative label: Absorption nebula
alternative label: Dark nebulae
alternative label: Dark clouds
alternative label: Absorption nebulae
alternative label: Dark nebula
broader: Nebulae
broader: Interstellar clouds
narrower: Bok globules
narrower: Infrared dark clouds
narrower: Cometary globules

Infrared dark clouds
type: Concept
broader: Dark interstellar clouds

Interstellar clouds
type: Concept
narrower: Dark interstellar clouds