Connectivity analysis of networked documents provides high quality link structure information, which is usually lost upon a content-based learning system. It is well known that combining links and content has the potential to improve text analysis. However, exploiting link structure is non-trivial because links are often noisy and sparse. Besides, it is difficult to balance the term-based content analysis and the link-based structure analysis to reap the benefit of both. We introduce a novel networked document clustering technique that integrates the content and link information in a unified optimization framework. Under this framework, a novel dimensionality reduction method called COntent & STructure COnstrained (Costco) Feature Projection is developed. In order to extract robust link information from sparse and noisy link graphs, two link analysis methods are introduced. Experiments on benchmark data and diverse real-world text corpora validate the effectiveness of proposed methods.