Ana Garcia‐Robles1 · Álvaro Solaz‐Garcia1 · Jorge Verdu‐Andres2 · José Luis Poveda Andrés3 · Antonio José Canada‐Martinez4 · Consuelo Cháfer Pericás1 · Henry Daniel Ponce‐Rodriguez3 · Máximo Vento1,5 · Pilar Sáenz González1, The association of salivary caffeine levels with serum concentrations in premature infants with apnea of prematurity Sep 2022 . European Journal of Pediatrics