000 00332nam a2200133Ia 4500
008 240227s9999 xx 000 0 und d
041 _a Sinhala
245 0 _aප්‍රතිශත භාවිතය
260 _bNIE,
_c1986
300 _a44p.;
_c28cm
650 _aScience-Maths
658 _aDistance Education
942 _cMD
999 _c98167
_d98167