7Cooper. R.L. 1979 Language Planning, Language Spread and Language Change. In Georgetown University Round Table on Language and Linguistics 1979:Language in Public Life. James E. Alatis and G. Richard Tucker ed. , 23-50. Washington: Georgetown University Press.
8Cooper, R. L. 1989 Language Planning and Social Change. Cambridge:Cambridge University Press.
9Harald Haarmann 1990 Language Planning in the Light of a General Theory of Language: a Methodological Network. In International Journal of the Sociology of Language 86:103-126.
10Heinz Kloss 1977 The Types of Language Planning. Language Planning and Building of National Language :Essays in Honor of Santiago Fonacier on His Ninety-Second Birthday, Bonifacio P. Sibayan and A. B. Gonzalez, eds. ,52- 59. Manila:the linguistic Society of the Philippines and Language Study Center.
