Fischer, O. C. M., Norde, M., & Perridon, H. C. B. (2004). Introduction. In search of grammaticalization. In O. Fischer, M. Norde, & H. Perridon (Eds.), Up and down the cline - The nature of grammaticalization (pp. 1-16). (Typological studies in language; No. 59). John Benjamins Publishing Co..