@article{JMLR:v16:ryan15a,
  author  = {Kenneth Joseph Ryan and Mark Vere Culp},
  title   = {On Semi-Supervised Linear Regression in Covariate Shift Problems},
  journal = {Journal of Machine Learning Research},
  year    = {2015},
  volume  = {16},
  number  = {99},
  pages   = {3183--3217},
  url     = {http://jmlr.org/papers/v16/ryan15a.html}
}