[Eubank R. (1988): Spline Smoothing and Nonparametric Regression. Marcel Dekker, New York.]Search in Google Scholar
[Afzal M., Yasin M., Sherawat S.M. (2002): Evaluation and Demonstration of Economic Threshold Level (ETL) for Chemical Control of Rice Stem Borers Scirpophagaincertulus Wlk. And S.innotata Wl. International Journal of Agriculture and Biology 3: 323-325.]Search in Google Scholar
[Simonoff J. (1995): Smoothing Methods of Statistics. Springer. New York.10.1007/978-1-4612-4026-6]Search in Google Scholar
[Thisted R.A. (1988): Elements of Statistical Computing. Chapman and Hall, New York.]Search in Google Scholar
[Weersink A., Deen W., Weaver S. (1991): Defining and Measuring Economic Threshold Levels. Canadian Journal of Agricultural Economics 39(4): 619-625.10.1111/j.1744-7976.1991.tb03613.x]Search in Google Scholar
