全文获取类型
| 收费全文 | 21437篇 |
| 免费 | 121篇 |
| 国内免费 | 8篇 |
专业分类
| 教育 | 15746篇 |
| 科学研究 | 2316篇 |
| 各国文化 | 79篇 |
| 体育 | 999篇 |
| 综合类 | 3篇 |
| 文化理论 | 454篇 |
| 信息传播 | 1969篇 |
出版年
| 2022年 | 55篇 |
| 2021年 | 114篇 |
| 2020年 | 157篇 |
| 2019年 | 217篇 |
| 2018年 | 2491篇 |
| 2017年 | 2403篇 |
| 2016年 | 1896篇 |
| 2015年 | 328篇 |
| 2014年 | 410篇 |
| 2013年 | 1761篇 |
| 2012年 | 469篇 |
| 2011年 | 1025篇 |
| 2010年 | 1091篇 |
| 2009年 | 646篇 |
| 2008年 | 900篇 |
| 2007年 | 1366篇 |
| 2006年 | 264篇 |
| 2005年 | 586篇 |
| 2004年 | 655篇 |
| 2003年 | 514篇 |
| 2002年 | 301篇 |
| 2001年 | 215篇 |
| 2000年 | 245篇 |
| 1999年 | 193篇 |
| 1998年 | 105篇 |
| 1997年 | 151篇 |
| 1996年 | 130篇 |
| 1995年 | 88篇 |
| 1994年 | 116篇 |
| 1993年 | 94篇 |
| 1992年 | 180篇 |
| 1991年 | 152篇 |
| 1990年 | 130篇 |
| 1989年 | 154篇 |
| 1988年 | 141篇 |
| 1987年 | 110篇 |
| 1986年 | 120篇 |
| 1985年 | 118篇 |
| 1984年 | 85篇 |
| 1983年 | 105篇 |
| 1982年 | 66篇 |
| 1981年 | 81篇 |
| 1980年 | 79篇 |
| 1979年 | 113篇 |
| 1978年 | 77篇 |
| 1977年 | 69篇 |
| 1976年 | 62篇 |
| 1975年 | 52篇 |
| 1974年 | 63篇 |
| 1973年 | 61篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
41.
42.
43.
44.
45.
46.
47.
48.
Kwafo-akoto KO 《Aslib proceedings》1988,40(4):105-110
Acquiring both published and unpublished documents produced in Africa is, generally, a difficult task due to the existing poor state of bibliographic control and the publishing industry. It is even more difficult to obtain unpublished documents in a specialized area of study such as demography--a diffuse area which cuts across several disciplines. This paper discusses the problems encountered on acquisition trips to some African countries to acquire unpublished population material. To help solve the problems, the Population Association of Africa must persuade its members to send copies of their publications to population libraries and documentation centers in their individual countries for dissemination to the other users in Africa. The various organizations and institutions in Africa engaged in the teaching and research of population studies should have an agreement to exchange copies of their theses. The Economic Commission for Africa (ECA) and the Organization of African Unity (OAU) should make representations to the various African member countries on the need to disseminate the results of vital censuses and surveys conducted. Finally, the Population Information Network for Africa (POPIN-AFRICA) with its coordinating unit at the population division of ECA should ensure that all the nodes of the network have the financial and other resources to be able to acquire the relevant documents needed for their operations. 相似文献
49.
Collins B Linton A Merril J Pomerantz K Winthrop S 《Medical reference services quarterly》1992,11(4):1-9
Computers are integral to medical practice, education, and research. While medical students learn computer skills during their training, many practicing physicians do not have the same computer experience. To familiarize this group with the exciting developments in medical informatics, the Himmelfarb Health Sciences Library and Department of Computer Medicine at the George Washington University Medical Center organized a workshop "Introducing Your Office Computer!" for attending physicians. The workshop featured a short lecture/video presentation on computer applications in medicine followed by a "computer fair" of five computer applications. Eleven physicians attended the workshop. Feedback was very positive; many called later to request more detailed instructions on using the programs demonstrated. It was a valuable experience for the staff, and new bridges were built between departments and clients. 相似文献
50.