@article{oai:tsukuba.repo.nii.ac.jp:00015763,
 author = {Dlab, Vlastimil and Ringel, Claus Michael},
 issue = {2},
 journal = {Tsukuba Journal of Mathematics},
 month = {Dec},
 pages = {489--496},
 title = {The Hochschild cocycle corresponding to a long exact sequence},
 volume = {14},
 year = {1990}
}