D. Hartvigsen recently gave an algorithm to find a C_{4}-free
2-factor in a bipartite graph and using this algorithm he
proved several nice theorems. Now we give a simple inductive proof for a
generalization of his Tutte-type theorem, and prove the corresponding
Ore-type theorem as well. The proof follows the idea
of the inductive proof for the Hall's theorem given by Halmos and Vaughn.

Bibtex entry:

@techreport{egres-01-13,

AUTHOR | = | {Kir{\'a}ly, Zolt{\'a}n}, |

TITLE | = | {$C_4$-free 2-factors in bipartite graphs}, |

NOTE | = | {{\tt www.cs.elte.hu/egres}}, |

INSTITUTION | = | {Egerv{\'a}ry Research Group, Budapest}, |

YEAR | = | {2001}, |

NUMBER | = | {TR-2001-13} |