Decreased erythrocyte Na + ,K( + )-ATPase activity associated with cellular potassium loss in extremely low birth weight infants with nonoliguric hyperkalemia - Stefano,J.L.; Norman,M.E.; Morales,M.C.; Goplerud,J.M.; Mishra,O.P.; Delivoria-Papadopoulos,M. (J Pediatr, 1993)