@book {Lehmann1993,
	title = {Theoretical bases of Indo-European linguistics},
	year = {1993},
	note = {<p>Includes bibliographical references (p. 298-315) and index</p>},
	pages = {XI, 324 },
	publisher = {Routledge},
	organization = {Routledge},
	edition = {1},
	address = {London ; New York},
	keywords = {Indo-European languages -- Research -- History, Proto-Indo-European language},
	author = {Lehmann, W. P.}
}
@inbook {Weinreich1968,
	title = {Empirical Foundation for a Theory of Language Change},
	booktitle = {Directions for historical linguistics: A symposium},
	year = {1968},
	pages = {95{\textendash}188},
	publisher = {Univ. of Texas Press},
	organization = {Univ. of Texas Press},
	address = {Austin, {TX}},
	keywords = {Historical linguistics, language change, езикова промяна, историческа лингвистика},
	author = {Weinreich, Uriel and Labov, William and Herzog, Marvin I.},
	editor = {Lehmann, W. P. and Malkeil, Yakov}
}
@book {Lehmann1952,
	title = {Proto-Indo-European Phonology},
	year = {1952},
	publisher = {University of Texas Press},
	organization = {University of Texas Press},
	address = {Austin, TX},
	url = {http://www.utexas.edu/cola/centers/lrc/books/piep00.html},
	author = {Lehmann, W. P.}
}
