@techreport{Saen04,
author = {F.~S\'{a}enz-P\'{e}rez},
institution = {Facultad de {I}nform\'{a}tica, {U}niversidad {C}omplutense de {M}adrid},
note = {{\tt http://www.fdi.ucm.es/profesor/fernan/DES/}},
number = {Technical Report 139-04},
title = {Datalog {E}ducational {S}ystem {V1.1.} {U}ser's {M}anual},
projects = {},
butype = {techreport},
year = {2004}
}