Sullivan minimal model; orientable fibration; TNCZ; negative derivation
We give an example of a space $X$ with the property that every orientable fibration with the fiber $X$ is rationally totally non-cohomologous to zero, while there exists a nontrivial derivation of the rational cohomology of $X$ of negative degree.
 I. Belegradek and V. Kapovitch: Obstructions to nonnegative curvature and rational homotopy theory
. J. Amer. Math. Soc. 16 (2003), 259–284. MR 1949160
 Y. Félix, S. Halperin and J. C. Thomas: Rational Homotopy Theory
. Springer GTM, 205, New York, 2001. MR 1802847
 M. Markl: Towards one conjecture on collapsing of the Serre spectral sequence
. Rend. Circ. Mat. Palermo (2) Suppl. 22 (1990), 151–159. MR 1061796
| Zbl 0705.55007
 M. Schlessinger and J. Stasheff: Deformation theory and rational homotopy type. Preprint.