Developed by Cambridge University Press, this textbook series is correlated to CEF (Common European Framework) rather than CLBs, however it is adaptable to PBLA settings. The Venture series comes highly recommended; it contains six-levels and is standards based, designed for adult and young-adult English learners. The series integrates language skills, with six clearly developed lessons for each unit.  It is suitable for continuous intake programs. (A free sample lesson can be ordered.)  The series includes a teacher's guide, student workbook and audio CD.  There is a cost to access these resources.