You will be given a definition of a task first, then some input of the task.
Given a sentence in English language, translate the sentence to Igbo language keeping the meaning of the original sentence intact

English sentence: Pre-treatment covariates can be included in the design and analysis stage of experiments; chapter 4 of Gerber and Green (2012) provides a good introduction to both approaches, and Casella (2008) provides a more in-depth treatment.
Output:
A puru itinye covariates na-eji gwugw eme ihe na nhazi na nyocha nke nyocha; isi nke 4 nke Gerber and Green (2012) enye nkwalite di mma ma biaruo nso, na Casella (2008) -enyekwu nhazi miri emi.