Modern Signs Press publishes Signing Exact English, a "dictionary" that features the "largest single collection of English signed vocabulary." Signing Exact English is itself a sign system "that matches signs with the English language." It differs significantly from American Sign Language. The book includes basics about sign language, sign systems, and deafness as well as more than 4,400 words, numbers, contractions, prefixes, and suffixes. Modern Signs Press also publishes a teacher manual and student workbook for those who want to expand this into a more complete course. See their website for details.