Harmonic sections of Riemannian vector bundles, and metrics of   Cheeger-Gromoll type
  We study harmonic sections of a Riemannian vector bundle whose total space is equipped with a 2-parameter family of metrics which includes both the Sasaki and Cheeger-Gromoll metrics. This enables the theory of harmonic unit sections to be extended to bundles with non-zero Euler class. 
M. Benyounes, E. Loubeau, C. M. Wood