Sis Readers is a series of retold and simplified stories which are classifed into 5 stages, each stage consists of 10 story books, in accordance with their degrees of difficulty. The selected stories are chosen among the world-wide known fairy tales, mythological narratives and short stories of famous authors.This series provides students and english learners of all ages with reading materials which help them improve their reading comprehension and vocabulary skills. Each book has its own extensive exercises and dictionary.