Hornikx, J., & Hendriks, B. (2015). Consumer Tweets about Brands: A Content Analysis of Sentiment Tweets about Goods and Services. Journal of Creative Communications, 10(2), 176–185. 

Examines the user generated content about brands and how this can be used for cocreation

Kozinets, R. V. (2002). The Field behind the Screen: Using Netnography for Marketing Research in Online Communities. Journal of Marketing Research, 39(1), 61–72.

Detailed exploration of netnography

Sprott, D., Czellar, S., & Spangenberg, E. (2009). The Importance of a General Measure of Brand Engagement on Market Behavior: Development and Validation of a Scale. Journal of Marketing Research, 46(1), 92–104.

Identifies how to measure brand engagement - critical for cocreation and equity

Supphellen, M. (2000). Understanding Core Brand Equity: Guidelines for In-depth Elicitation of Brand Associations. International Journal of Market Research, 42(3), 1–14.

Overview of how to measure core brand associations