全文获取类型
收费全文 | 8638篇 |
免费 | 315篇 |
专业分类
8953篇 |
出版年
2020年 | 123篇 |
2019年 | 128篇 |
2018年 | 185篇 |
2017年 | 218篇 |
2016年 | 217篇 |
2015年 | 175篇 |
2014年 | 142篇 |
2013年 | 2332篇 |
2012年 | 210篇 |
2011年 | 214篇 |
2010年 | 211篇 |
2009年 | 253篇 |
2008年 | 280篇 |
2007年 | 209篇 |
2006年 | 165篇 |
2005年 | 119篇 |
2004年 | 113篇 |
2003年 | 115篇 |
2002年 | 112篇 |
2001年 | 142篇 |
2000年 | 124篇 |
1999年 | 130篇 |
1998年 | 100篇 |
1997年 | 71篇 |
1996年 | 101篇 |
1995年 | 95篇 |
1994年 | 88篇 |
1993年 | 100篇 |
1992年 | 80篇 |
1991年 | 65篇 |
1990年 | 60篇 |
1989年 | 89篇 |
1988年 | 73篇 |
1987年 | 92篇 |
1986年 | 86篇 |
1985年 | 111篇 |
1984年 | 135篇 |
1983年 | 135篇 |
1982年 | 105篇 |
1981年 | 106篇 |
1980年 | 114篇 |
1979年 | 102篇 |
1978年 | 116篇 |
1977年 | 97篇 |
1976年 | 114篇 |
1975年 | 99篇 |
1974年 | 71篇 |
1973年 | 63篇 |
1972年 | 64篇 |
1971年 | 59篇 |
排序方式: 共有8953条查询结果,搜索用时 15 毫秒
31.
32.
33.
"An empirical test of the effects of exogenous shocks upon a region's population size is conducted in the framework of an equilibrium locational model. The model emphasizes the separation of endogenous from exogenous factors, a point omitted in most empirical studies of aggregate migration. Exogenous changes are manifested in the local relative cost of living and the local relative unemployment rate. Hypotheses are tested using a national sample of youth, in addition to census, data [for the United States]. Surprisingly, a simple measure of the size of shock to a regional economy has the greatest explanatory power compared to more sophisticated measures based on prior business cycles." 相似文献
34.
Norman R. Cloutier 《Journal of regional science》1988,28(3):415-419
ABSTRACT. The distribution of above-median income groups can be described accurately by OLS regression of the Pareto distribution. The excellent fit of log-linear regression has led some researchers to conclude that extrapolated income measures in the open end of the distribution are reliable. The analysis of income distribution data for metropolitan areas reveals: (1) that OLS tends to consistently overestimate the number of families in the tail, and (2) that the overestimation can have serious implications for hypothesis testing. 相似文献
35.
36.
"This paper presents a two-sector dynamic model of regional population change. The model contains a migration equation, an earnings equation, and an amenity equation for each region. In the context of this model, migration is seen as a disequilibrium process through which the regional populations move towards equilibrium positions. Migration occurs when one region is perceived to be superior to the other on the basis of its earnings and amenity levels. Equilibrium is achieved when population movements between the regions eliminate any differences in their relative attractiveness. A comparative-static analysis of the model is presented to analyze the effects of policy changes and exogenous shocks on the distribution of population among the regions." The geographical focus is on the United States. 相似文献
37.
38.
39.
40.