1.
A Linear-Time Algorithm for Gaussian and Non-Gaussian Trait Evolution Models
by Ho, Lam si Tung
Systematic biology, 2014-05-01, Vol.63 (3), p.397-408

2.
A Relaxed Directional Random Walk Model for Phylogenetic Trait Evolution
by Gill, Mandev S
Systematic biology, 2017-05-01, Vol.66 (3), p.299-319
