Alan Baker and Gisbert Wüstholz, Logarithmic Forms and Diophantine Geometry, New Mathematical Monographs 9, Cambridge University Press, 2007, ISBN 978-0-521-88268-2.
An explicit result by Baker and Wüstholz for a linear form Λ with integer coefficients yields a lower bound of the form
Alan Baker and Gisbert Wüstholz, Logarithmic Forms and Diophantine Geometry, New Mathematical Monographs 9, Cambridge University Press, 2007, ISBN 978-0-521-88268-2
He proved the Analytic subgroup theorem which together with similar other comprehensive results of this type has many applications to transcendental number theory.