(1) A Course in Romance Linguistics: A Diachronic View Frederick B. Agard ISBN: 9780878400744 Georgetown University Press View at publisher
(2) A Dictionary of Informal Brazilian Portuguese with English Index Bobby John Chamberlain and Ronald M. Harmon, Editors ISBN: 9780878403448 Georgetown University Press View at publisher
(3) Analytic Syntax Jespersen, Otto ISBN: 9780226398808 University of Chicago Press View at publisher
(4) Language Bloomfield, Leonard ISBN: 9780226060675 University of Chicago Press View at publisher