The number of articles and documents included in the bibliography is extensive; however, unpublished documents have not been reviewed, as well as documents in languages other than English or Spanish, so a few documents may not have been reviewed.
El número de artículos y documentos incluidos en la bibliografía es amplio, sin embargo, no se ha revisado la literatura gris ni los documentos en idiomas distintos al inglés y español, lo que posibilita que algunos documentos no hayan sido revisados.