Here are a few case study and research articles:
A Little Article Marketing Research
Follow My Footsteps In Making Money Online
Follow My Footsteps – Day 4 – Using Social Bookmark Sites
Follow My Footsteps – Day 8 – Choosing a New Niche
Follow My Footsteps – Day 10 – Finding a Profitable Niche
Follow My Footsteps – Day 12 – Article Marketing
Follow My Footsteps – Day 20 – Showing Real Progress
Follow My Footsteps – Day 29 – Gaining Momentum
Follow My Footsteps – Day 33 – Keyword Research
Link Building Strategy : Case Study
Plug In Profit Site Poll Questions