Proficiency Masterclass Workbook with Key and Audio CD Pack
Kathy Gude, Michael Duckworth
Proficiency Masterclass Student's Book
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Proficiency Scales for the New Science Standards: A Framework for Science Instruction and Assessment, Paperback
Robert Marzano
Proficiency in personal survival techniques
International Maritime Organization
New Proficiency Passkey - Student's Book
Nick Kenny
Objective Proficiency (Teacher's Book)
Annette Capel, Wendy Sharp