Size and Variable Ordering of OBDDs Representing Treshold Functions. - Yasuhiko Takenaga; Mitsushi Nouzoe; Shuzo Yajima (COCOON, 1997)

Optimizing OBDDs Is Still Intractable for Monotone Functions. - Kazuo Iwama; Mitsushi Nouzoe; Shuzo Yajima (MFCS, 1998)