Section 290.440 - Female may recover wages, when - burden of proof1. Any employer who violates section 290.410 is liable to the female employee affected in the amount of the wages of which the female employee is deprived by reason of the violation.2. Any female employee receiving less than the wage to which she is entitled under sections 290.400 to 290.450 may recover in a civil action the balance of the wages, together with the costs of suit, notwithstanding any agreement to work for a lesser wage.3. The burden of proof shall be upon the person bringing the claim to establish that the differentiation in rate of pay is based upon the factor of sex and not upon other differences or factors.L. 1963 p. 416 §§ 3, 6, 8