00321nas a2200121   4500000000100000008004100001260002700042100001100069700001200080700001000092245008600102300001100188       2010                            d  bScience PressaBeijing1 aYan L.1 aZeng Y.1 aLi L.00aResearch on relation between social-economic status and health on Chinese elderly  a116-35