2021. Using Different Threshold Value in Comparison Some of Methods Wavelet Estimation for Non Parametric Regression Function with Missing Data. Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ). 37, 1 (Oct. 2021), 1–33. DOI:https://doi.org/10.55562/jrucs.v37i1.233.