中国科学院数学与系统科学研究院期刊网
Graphs of NMS Flows on S3with Knotted Saddle Orbits and No Heteroclinic Trajectories
B. CAMPOS, P. VINDEL
Acta Mathematica Sinica . 2007, (12): 2213 -2224 .  DOI: 10.1007/s10114-007-0969-x