Text ( visual ) : unmediated Factor analysis of the Test of English as a Foreign Language for several language groups / Spencer S. Swinton, Donald E. Powers. -- Princeton, N.J. : Educational Testing Service , c1980. -- iii, 79 p. : ill. ; 28 cm. -- (TOEFL research reports ; report 6). -- "December 1980"--Cover ; "RR 80-32." ; Includes bibliographical references (p. 27-28). -- (BA23411529) ; https://ci.nii.ac.jp/ncid/BA23411529 Author Heading(s): Swinton, Spencer S. ; Powers, Donald E.