Data Sets for Book Examples, available in Stata format and other formats at:
https://dataverse.harvard.edu/dataverse/crt
The Stata routine clan by Thompson JA et al. performs various two-stage analyses for covariate adjustment; from within Stata, just enter lookup clan .
Link to Greene SAS Macro for obtaining highly constrained randomizations:
https://github.com/ejgreene/ccr-sas
The Stata routine ccrand, SJ17-2 st0484, by Lorenz and Gabrysch is also good for highly constrained randomization.
Chaudhary/Moulton SAS Macro for obtaining highly constrained randomizations:
Download SAS Macro (note: this is a .docx file, you'll need to copy into a text .sas file (this website provider only allows media files).