Foto N. Afrati Rada Chirkova Manolis Gergatsoulis Vassia Pavlaki View selection for <i>real</i> conjunctive queries. 289-321 2007 44 Acta Inf. 5 http://dx.doi.org/10.1007/s00236-007-0046-z db/journals/acta/acta44.html#AfratiCGP07