Zou, W., & Schechter, M. Critical point theory and its applications.
Cita Chicago (17th ed.)Zou, Wenming, i Martin Schechter. Critical Point Theory and Its Applications.
Cita MLA (8th ed.)Zou, Wenming, i Martin Schechter. Critical Point Theory and Its Applications.
Atenció: Aquestes cites poden no estar 100% correctes.