sciencedirect数据库
ScienceDirect is the world\'s leading source for scientific, technical, and medical research. Explore journals, books and articles.www.sciencedirect.com
- 2015-12-19 - 收藏
springer数据库
Providing researchers with access to millions of scientific documents from journals, books, series, protocols and reference works.link.springer.com
- 2015-12-19 - 收藏
258平台Socks5代理
258平台是出售socks5代理IP的网站,销售的IP适合,游戏代理、网页代理、代理软件,平台出售各个国家S5代理IP,欧洲S5代理、美国S5代理,全世界各国S5都有！www.258s5.com
- 2015-12-06 - 收藏
Thinkstock官网
ThinkStockPhotos:在线免版税图片素材网是一家提供数千万张高清图片素材的图片供应商，提供动植物、插图、建筑、背景、概念摄影、人与生活方式、教育、娱乐、节日庆典、旅游等丰富的图片类别。Download royalty-free images, high resolution stock photos, vector art and illustrations from Thinkstock . High quality, affordable stock photography subscriptions.
- 2015-12-02 - 收藏
ArtGraphica网站
ArtGraphica 网站是一个致力于提供优质的艺术教育和来自不同背景和年龄段的艺术家们的作品，主要涉及写生、素描、油画、铅笔、水彩、粉彩、亚克力、木炭、水墨和绘画理论课程等。For more than ten years artgraphica has provided a free education for art students and a great resource for teachers, helping educate artists of all ages and abilities to improve sketching drawing and painting skills.
- 2015-11-24 - 收藏