Twenty-six papers were included in the review, covering 13 countries (the former USSR, the Czech Republic, Poland, and Romania in Eastern Europe, and Denmark, France, Germany, Italy, the Netherlands, Northern Ireland, Spain, Sweden, and Switzerland in Western Europe) in the period from 1988-2001.
En la revisión se incluyeron veintiséis documentos, que abarcaban a 13 países (la ex Unión Soviética, la República Checa, Polonia y Rumania en Europa del este, y Dinamarca, Francia, Alemania, Italia, Holanda, Irlanda del Norte, España, Suecia y Suiza en Europa occidental) en el período comprendido entre 1988 y 2001.