Katz E R, Brenner S
Mol Gen Genet. 1975 Dec 30;143(1):101-4. doi: 10.1007/BF00269426.
In this report the herefore uncharacterized mutants at the beginning of the rIIB cistron of bacteriophage T4 have been connected to the main part of the map and have been shown not to be in any way unusual. The temperature sensitive mutant HD263 appears to be the earliest mutant in the cistron.