Cita APA (7th ed.)

Christensen, L. B., & Johnson, R. B. (2011). Research methods, design, and analysis (Eleventh edition.). Pearson Education, Inc.

Cita Chicago (17th ed.)

Christensen, Larry B., i R. Burke Johnson. Research Methods, Design, and Analysis. Eleventh edition. Boston, Massachusetts: Pearson Education, Inc, 2011.

Cita MLA (9th ed.)

Christensen, Larry B., i R. Burke Johnson. Research Methods, Design, and Analysis. Eleventh edition. Pearson Education, Inc, 2011.