  We present analytic results for three-loop fermionic corrections to the
heavy-light form factors in perturbative quantum chromodynamics. Specifically,
we present all light quark contributions and contributions from two heavy quark
loops. We use the method of differential equations to compute all relevant
three-loop master integrals. The results for all these contributions are
expressed in terms of harmonic polylogarithms and generalized harmonic
polylogarithms.
