itun.es/i6g37tN itun.es/i6SD8CJ
English Essentials is an iTunes U and iBooks Textbooks series written by Dr. Alfred Siha. Both English Essentials iTunes U courses have hundreds of thousands of subscribers worldwide, have over one million total user actions, and have been honored as "Best of iTunes U" by Apple. They have both been consistently ranked in the top 10 and top 20 iTunes U courses worldwide, and have peaked at number two and number one in the world.

English Essentials: Writing iBooks Textbook has consistently been ranked in the top 50 purchased textbooks worldwide and, along with a private iTunes U course, has been used as a primary textbook for developmental writing courses at HACC, Central Pennsylvania's Community College.