全文获取类型
收费全文 | 3619篇 |
免费 | 136篇 |
出版年
2020年 | 57篇 |
2019年 | 65篇 |
2018年 | 95篇 |
2017年 | 98篇 |
2016年 | 107篇 |
2015年 | 81篇 |
2014年 | 74篇 |
2013年 | 1194篇 |
2012年 | 80篇 |
2011年 | 98篇 |
2010年 | 79篇 |
2009年 | 76篇 |
2008年 | 81篇 |
2007年 | 58篇 |
2006年 | 60篇 |
2005年 | 41篇 |
2004年 | 38篇 |
2003年 | 33篇 |
2002年 | 45篇 |
2001年 | 54篇 |
2000年 | 31篇 |
1999年 | 43篇 |
1998年 | 24篇 |
1997年 | 32篇 |
1996年 | 26篇 |
1995年 | 22篇 |
1994年 | 38篇 |
1993年 | 32篇 |
1992年 | 35篇 |
1991年 | 21篇 |
1990年 | 33篇 |
1989年 | 28篇 |
1988年 | 30篇 |
1987年 | 32篇 |
1986年 | 30篇 |
1985年 | 33篇 |
1984年 | 53篇 |
1983年 | 55篇 |
1982年 | 47篇 |
1981年 | 39篇 |
1980年 | 37篇 |
1979年 | 41篇 |
1978年 | 42篇 |
1977年 | 31篇 |
1976年 | 32篇 |
1975年 | 34篇 |
1973年 | 27篇 |
1972年 | 31篇 |
1971年 | 21篇 |
1970年 | 32篇 |
排序方式: 共有3755条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
The relative importance and the spheres of influence of the urban centres within some specified region, such as a country, are intriguing topics of investigation. Webber (1964) indicated that the ordering of centres within a country is not possible, since “the spatial extent of each [urban] realm is ambiguous, shifting instantaneously as participants in the realm's many interest-communities make new contacts, trade with different friends, or read different publications.’ We suspect, however, that there is considerable order in the communication links among the larger centres within a country. For example, Canada's leaders in business, governments, and the arts tend to move through a hierarchy of centres to end up in Toronto, Ottawa, Montreal, Vancouver, or some other large city, depending upon the particular field in which they work. All urban centres are linked to Ottawa, which is at the apex of political power, and to large urban centres, such as Toronto and Montreal, which predominate in the economic realm. The major purpose of this paper is to derive a nodal structure for seventeen major Canadian cities, based on newspaper datelines. By utilizing these particular information flows, the analyses also shed light on possible differences between the anglophone and francophone communications networks. 相似文献
996.
997.
998.
999.
1000.
R. G. KILLICK H. E. W. CRAWFORD K. FLAVIN H. GINGER A. LUPTON C. MACLAUGHLIN R. MONTAGUE J. A. MOON M. A. WOODBURN 《Arabian Archaeology and Epigraphy》1991,2(2):107-137
Preliminary results are presented of the first season's excavations at Saar, Bahrain, by the London-Bahrain Archaeological Expedition. Saar is a single-period settlement dating to the early part of the second millennium BC. A short introduction to the history of excavation at Saar is followed by an account of the 1990 excavations in the temple area and in three areas of town housing. The main pottery types are discussed and some general conclusions then drawn about the settlement. 相似文献