The Cambridge encyclopedia of language / David Crystal. - Cambridge ; New York : Cambridge University Press, 1987. - viii, 472 p. : ill. ; 28 cm.см.. - ბიბლიოგრ.: გვ. 448-452. - ISBN 0-521-42443-7[MFN: 124982]
UDC: 81(031)
IV 3.236 = A 81(031)/C-87 - English and Anglo-American Literature Reading Hall