1Strevens P. ESP after twenty years: a re - appraisal [ A ] , in Tichoo M. ( ed. ) ESP: State of the Art [ C ]. Singa- pore: SEAMEO Regional Language Centre, 1988.
2Hutchinson, T, &Waters, A. English for Special Purpose : a learning - centred approach [ M ]. Cambridge : Cam- bridge University Press, 1987.