000 00313nam a2200121 a 4500
005 20140414132113.0
008 110817s19uu xx 00 eng d
050 _aREF 503
_bL87 1990
245 _aLooking at structures.
260 _aSingapore :
_bWorl book,
_c1990.
440 _aYoung Scientist
999 _c114840
_d114840