"spectral" - key terms from Wikipedia

adaptive spectral	perceptual entropy coding
energy spectral	density
power spectral	density
pure spectral	colors
spectral
spectral	analysis
spectral	band replication
spectral	class
spectral	classes
spectral	classification
spectral	clustering
spectral	coherence
spectral	color
spectral	colors
spectral	density
spectral	distribution of energy
spectral	efficiency
spectral	evidence
spectral	hues
spectral	indigo
spectral	leakage
spectral	line
spectral	lines
spectral	locus
spectral	method
spectral	music
spectral	norm
spectral	power distribution
spectral	range
spectral	realm
spectral	sensitivity
spectral	space pirates
spectral	theorem
spectral	tiger
spectral	type
spectral	types
spectral	width
those for which the spectral