If you are considering buying a pair, make sure to read this Beyerdynamic DT-990 Pro review beforehand.
Beyerdynamic DT990 Pro Review (headphone)
Beyerdynamic DT 880 Edition 600 Ohm Review — World Bolding
Beyerdynamic DT 990 Pro 80 Ohm Headphones Review
Beyerdynamic DT 880 Pro studio headphones review
Beyerdynamic DT 990 PRO review - SoundGuys
Focusrite Scarlett 2i2 & 250 Ohm Headphones
Beyerdynamic DT 990 Pro Review - Produce Like A Pro
Beyerdynamic DT 990 PRO Studio Headphones (Ninja Black, Limited Edition) Bundle
Beyerdynamic DT990 Pro Review (headphone)
Archimago's Musings: RETRO: Beyerdynamic DT 990, 600Ω, classic open-back circumaural headphones (circa 1991).