A paywall that prevents access to the content behind it, except by subscribers; for, example subscribers to the online version of a newspaper. This contrasts with a soft paywall where some access is allowed.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。