o ). ▁ 7 ▁Mon os , ▁ 2 0 0 2 . ▁ ▁Com ic ▁books ▁ ▁Sex or ama : ▁El ▁manual ▁sexual ▁de ▁Manuel ▁Bart ual . ▁El ▁J ue ves , ▁ 2 0 0 9 ▁ ▁¡ E sc ucha ▁esto ! ▁Ast iber ri , ▁ 2 0 0 9 . ▁ ▁Sex or ama . ▁Conse jos ▁sexual es ▁para ▁ch aval as ▁y ▁ch av ales ▁( A st iber ri , ▁ 2 0 1 2 ) ▁ ▁Sex or ama . ▁Don de ▁cab en ▁dos ▁cab en ▁tres ▁( A st iber ri , ▁ 2 0 1 3 ) ▁ ▁References ▁ ▁External ▁links ▁ ▁Bart ual ▁in ▁Lamb iek ▁com iclopedia ▁ ▁Category : 1 9 7 9 ▁birth s ▁Category : L iving ▁people ▁Category : Pe ople ▁from ▁Val encia ▁Category : Span ish ▁com ics ▁artists ▁Category : Span ish ▁com ics ▁writers <0x0A> </s> ▁A ▁convenient ▁notation ▁for ▁the or etic ▁sched uling ▁problems ▁was ▁introduced ▁by ▁Ron ald ▁Graham , ▁Eug ene ▁Law ler , ▁Jan ▁K arel ▁Len stra ▁and ▁Alexander ▁R in no oy ▁Kan ▁in . ▁It ▁consists ▁of ▁three ▁fields : ▁α , ▁ β ▁and ▁ γ . ▁ ▁Each ▁field ▁may ▁be ▁a ▁comma ▁separated ▁list ▁of ▁words . ▁The ▁α ▁field ▁describes ▁the ▁machine ▁environment , ▁ β ▁the ▁job ▁characteristics ▁and ▁constraints , ▁and ▁ γ ▁the ▁objective ▁function . ▁ ▁Since ▁its ▁introduction ▁in ▁the ▁late