@article {liu2011regression,
	title = {Regression with fractional polynomials when interactions are erroneously omitted},
	journal = {Journal of Statistical Planning and Inference},
	year = {2011},
	publisher = {Elsevier},
	doi = {10.1016/j.jspi.2011.12.012},
	author = {Liu, J. and Gustafson, P.}
}
