The construction of all the projective spanning trees of a given digraph
  In the present paper we consider the problem of constructing all the projective rooted spanning trees of a given graph. We propose an algorithm based on reducing this problem to the problem of constructing all the maximal independent sets of a certain derived graph. We also offer an algorithm for step-by-step growing the spanning trees that sifts, at each step, any sub-trees non-extendable to projective spanning trees. The proposed algorithms were applied for analyzing the possible variants of the syntactic subordination of nouns through prepositions . 
Mikhail A. Antonets, Grigoriy P. Kogan
math.CO