by R.M.W. Dixon
Part of a three-volume magnum opus on linguistic description and typology from one of Australia's leading linguists. The series is destined to become the guide to writing descriptive grammars.
Despite "theory" in the title, this could better be described as "anti-theoretical", with Dixon's characteristic dig at linguists who do theory first.
I'm almost finished this volume and about to start Volume 2: Grammatical Topics.
by Franklin M. Harold
A follow on to the author's The Way of the Cell focusing on theories of how cells came about.
Haven't started reading this yet.
by Robert S. P. Beekes
A reconstruction of the non-Indo-European language believed to have been spoken by the Greeks prior to Indo-European, based on evidence in Ancient Greek.
by Pavel Grinfeld
A wonderful introduction to tensor calculus (I haven't got to the bits on moving surfaces yet) that balances the algebraic and geometric foundations and focuses on building intuitions rather than formalization.