Vailaya A, Sajonz P, Sudah O, Capodanno V, Helmy R, Antia FD. Exploiting pH mismatch in preparative high-performance liquid chromatographic recovery of ertapenem from mother liquor streams. J Chromatogr A. 2005 Jun 24;1079(1-2):80–91. doi: 10.1016/j.chroma.2005.04.004. PMID: 16038294.