%0 Journal Article %J Language Learning %D 2019 %T Specifying the Academic Language Skills That Support Text Understanding in the Middle Grades: The Design and Validation of the Core Academic Language Skills Construct and Instrument %A Barr, Christopher %A Uccelli, Paola %A Galloway, Emily %B Language Learning %V 69 %8 06 %G eng %R 10.1111/lang.12365