1899 Jrnl. Amer. Chem. Soc. 21 649 Certain salts of carboxy-acids.

1922 J. J. Sudborough Bernthsen's Text-bk. Org. Chem. (new ed.) xxx. 508 The amino-, hydroxy-, and carboxy-derivatives of triphenyl-methane are the leuco-bases obtained from such dyes as rosaniline, aurine, malachite green, &c.

1955 B. C. L. Kemp Elem. Org. Chem. (new ed.) xx. 274 Carboxy-acids may be obtained by hydrolysis of cyanogen derivatives prepared as above.

1987 R. Bartha & R. M. Atlas in D. F. Boesch & N. Rabalais Long-Term Environmental Effects Offshore Oil & Gas Devel. vii. 300 As in the case of alkanes, the terminal carbon is oxidized through the hydroxy- and oxo-stages to a carboxy group.

2004 Science 5 Mar. 1455/3 FIH-1..uses oxygen to add hydroxyl groups to an asparagine residue near the carboxy end of HIF-1α.