Content validation of the operational definitions of the nursing diagnoses of activity intolerance, excess fluid volume, and decreased cardiac output in patients with heart failure - Souza, Vanessa de; Zeitoun, Sandra Salloum; Lopes, Camila Takáo; Oliveira, Ana Paula Dias de; Lopes, Juliana de Lima; Barros, Alba Lúcia Bottura Leite de (International Journal of Nursing Knowledge, 2014)