Optional professional publication (in the field of the studied area, min. ten relevant sources) written by a native speaker in the last 5 years
MCCARTHY, Michael a Felicity O'DELL. Academic vocabulary in use: vocabulary reference and practice : self-study and classroom use. Second edition. Cambridge: Cambridge University Press, 2016. ISBN 978-1-107-59166-0.
IBBOTSON, Mark. Professional English in Use Engineering. Cambridge, Cambridge University Press 2009. 112 p. ISBN 978-0521734882.