Helliconia
The trilogy consists of the books "Helliconia Spring" ( published in 1982 ) , "Helliconia Summer" ( 1983 ) , and "Helliconia Winter" ( 1985 ) . 
<triplet> Helliconia <subj> Helliconia Summer <obj> has part <triplet> Helliconia <subj> Helliconia Summer <obj> has part