Coexistence of two accessory flexor pollicis longus heads or coexistence of two-headed flexor pollicis longus with an unrecognized anatomical structure? | SpringerLink
Anatomy of the Flexor Pollicis Longus — OrthopaedicPrinciples.com
Flexor Pollicis Longus - UW Radiology
The prevalence and anatomical characteristics of the accessory head of the flexor pollicis longus muscle: a meta-analysis [PeerJ]