Maximum likelihood estimation for univariate reducible
stochastic differential equation models. Discrete, possibly noisy
observations, not necessarily evenly spaced in time. Can fit
multiple individuals/units with global and local parameters, by
fixed-effects or mixed-effects methods. Ref.: Garcia, O. (2019)
"Estimating reducible stochastic differential equations by
conversion to a least-squares problem", Computational Statistics
34(1): 23-46,