Graded readers are very useful for practising extensive reading. Extensive reading has several benefits, for example, getting a lot of comprehensible input.
I have found several series of graded readers that use simplified Chinese characters, such as Chinese Breeze and the series by the Foreign Languages Teaching and Research Press (FLTRP). However, I have not found any graded readers that use traditional Chinese characters. (I have found basal readers for Chinese/Taiwanese schoolchildren, but that is not the same thing.)
Can anybody suggest graded readers written in traditional Chinese characters?