Improved boosted two parameter Breitung estimator: An application to the crude oil prices Talha Omer, Jönköping International Business School; Pär Henrik Sjölander, Jönköping International Business School, Jönköping University, Sweden; Kristofer Månsson, Jönköping International Business School, Jönköping University, Sweden; B M Golam Kibria, Florida International University FIU, Miami, USA