For attenting students (A1/A2):
Clare Walsh and Lindsay Warwick, Gold Preliminary B1 – New Edition (with 2020 Exam Specifications), Coursebook with MyEnglishLab (MEL) access, Pearson (ISBN 9781292217826)
For non-attending students (already B1):
B1 Preliminary 1. Authentic Practice Tests for the Revised 2020 Exam, Student’s Book with Answers, with Audio and Resource Bank, Cambridge University Press (ISBN: 9781108676410)