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While B ab c2 can be easily assessed experimentally, p$_{c}$ 26 and γ 11 are difficult to determine. By fixing p$_{c}$ to a realistic value, γ can be estimated from the difference between 39 B$_{ρ}$$_{=0}$ and B ab $_{c2}$, or, alternatively, by estimating γ from T$_{c}$ , p$_{c}$ can be obtained $^{9,26}$. However, any uncertainty in one quantity induces a similar error in the other one; furthermore Equ. 3 was derived for a perfectly homogeneous material and neglecting the influence of thermal fluctuations. Both effects increase the difference between B$_{ρ}$$_{=0}$ and B$_{c2}$ . Thermal fluctuations, which result in a difference between the intrinsic B$_{c2}$ and B$_{irr}$ in each grain, generally increase with B$_{c2}$ (the importance of fluctuations is quantified by the Ginzburg number 40 Gi ∝ B 3 $_{c2}$) and T . A successful description of the resistive transition by Equ. 3 thus requires a homogeneous material (narrow superconducting zero field transition), a moderate upper critical field, and temperatures well below T$_{c}$ . 

