An oriented graph $overleftarrow{G}$ is a simple undirected graph $G$ with an orientation, which assigns to each edge a direction so that $overleftarrow{G}$ becomes a directed graph. $G$ is called the underlying graph of $overleftarrow{G}$ and we denote by $S(overleftarrow{G})$ the skew-adjacency matrix of $overleftarrow{G}$ and its spectrum $Sp(overleftarrow{G})$ is called the skew-spectrum of $overleftarrow{G}$. In this paper, the coefficients of the characteristic polynomial of the skew-adjacency matrix $S(overleftarrow{G}) $ are given in terms of $overleftarrow{G}$ and as its applications, new combinatorial proofs of known results are obtained and new families of oriented bipartite graphs $overleftarrow{G}$ with $Sp(overleftarrow{G})={f i} Sp(G) $ are given.
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