McGraw Hill
Mc Graw Hill: Conventions of Standard English: Avoiding Vague Pronoun References
Read about vague pronoun references then click the practice button to practice what you've learned.
University of Richmond
University of Richmond: Confusing Pronouns
This site discusses the need to avoid ambiguous pronoun references. Includes a helpful rewriting examples. Brief, but informative and factual.
Capital Community College Foundation
Guide to Grammar and Writing: Consistency of Tense and Pronoun
Brief instruction on maintaining pronoun and verb tense consistency. Links to additional help and quiz are included.