Select with data from associative tables

Question

I am creating a small database to store the books I own at home, but I came across the following situation: I have two associative tables, a call self-published, that allows the same book to have several authors and a call genero_book, which allows a particular book to be part of one or more genres (two, to be exact). My problem is time to create a SELECT that brings the information from the books (for example: authors, page Qtd), but also brings what genres this book is part of. I managed to create the query, but my code is repeating several times the authors and the generos of the books. What would be causing this repetition?

Follow my code (I am using MYSQL):

SELECT group_concat(a.nome) as 'Autores', l.titulo as 'Título', l.pag as 'Páginas', group_concat(g.tipo), e.nome as 'Editora' 
FROM autor_livro al
INNER JOIN autor a ON a.id_autor = al.autor
INNER JOIN livro l ON l.id_livro = al.livro
INNER JOIN editora e ON e.id_editora = l.editora
INNER JOIN genero_livro gl ON gl.livro = al.livro
INNER JOIN genero g ON g.id_genero = gl.genero
GROUP BY al.livro;