APA (7th ed.) Citation
ebrary, Inc, Gutzman, A. D., Muller, A., Pfledderer, D., & Gibbons, T. (2002). Buyers' guide to search engine optimization firms: Who should you hire? how much should you pay? (2nd ed.). MarketingSherpa.
Chicago Style (17th ed.) Citation
ebrary, Inc, Alexis D. Gutzman, Anthony Muller, Donna Pfledderer, and Tim Gibbons. Buyers' Guide to Search Engine Optimization Firms: Who Should You Hire? How Much Should You Pay? 2nd ed. Portsmouth, R.I.: MarketingSherpa, 2002.
MLA (9th ed.) Citation
ebrary, Inc, et al. Buyers' Guide to Search Engine Optimization Firms: Who Should You Hire? How Much Should You Pay? 2nd ed. MarketingSherpa, 2002.
Warning: These citations may not always be 100% accurate.