Density Calculations for (Na, K)BH4 + (Na, K)BO2 + (Na, K)OH + H2O Solutions Used in Hydrogen Power Engineering Churikov, A.V.; Ivanishchev, A.V.; Gamayunova, I.M.; Ushakov, A.V.; Journal of Chemical & Engineering Data 2011, 56, 3984-3993