Edicion especial por el XX aniversario de la publicacion del primer libro de la serie de Harry Potter: Harry Potter y la piedra filosofal. Son cuatro libros que contienen cada uno el texto integro mas material extra con informacion sobre cada escuela: historia, alumnos destacados, etc., en unas 30 paginas aproximadamente. Es decir, el material extra es diferente en cada libro. / Special edition for the 20th anniversary of the publication of the Harry Potter series first book: Harry Potter and the Philosopher's Stone. There are four books and each book contains the complete text plus extra material with information about each school: history, outstanding students, etc., in about 30 pages. The extra material is different in each book. Harry Potter and the Philosopher's Stone has been read and loved by every new generation ever since.