Equation

Reference

$R=\frac{2.5P^2}{100\left(0.073P+0.73\right)}$

(Bols, 1978)

$R=-3172+7.562P$

(Mikhailova et al., 1997)

$R=-944+3.08P$

(Torri et al., 2006)

$R=0.04830P^{1.61},P<850\text{mm}$

(Kenneth G. Renard & Freimund, 1994)

$R=\left(0.5\pm 0.05\right)\ast P$

(Roose, 1976)

$R=9.08\ast 0.0115P^{1.4947}$

(Jung et al., 1983)

$R=23.61\ast {\text{e}}^{0.0048P}$

(Eltaif et al., 2010)