Given the task definition and input, reply with output. In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

He was perhaps best known for his book " Literacy in Theory and Practice " ( 1984 ) .

During his career , he mainly worked on literacy in both theoretical and applied perspectives , and is perhaps best known for his book " Literacy in Theory and Practice " ( 1984 ) .