Heinemeyer EA, Richter D (1978). "Characterization of the guanosine 5'-triphosphate 3′-diphosphate and guanosine 5′-diphosphate 3′-diphosphate degradation reaction catalyzed by a specific pyrophosphorylase from Escherichia coli". Biochemistry. 17 (25): 5368–72. doi:10.1021/bi00618a007. PMID365225.
Heinemeyer EA, Richter D (1978). "Characterization of the guanosine 5'-triphosphate 3′-diphosphate and guanosine 5′-diphosphate 3′-diphosphate degradation reaction catalyzed by a specific pyrophosphorylase from Escherichia coli". Biochemistry. 17 (25): 5368–72. doi:10.1021/bi00618a007. PMID365225.