Here's a fairly detailed paper with links to many of the laws and court decision...

Sacho on Sept 14, 2017 | parent | context | favorite | on: EFF, ACLU Sue Over Warrantless Phone, Laptop Searc...

Here's a fairly detailed paper with links to many of the laws and court decisions that are the bedrock of the border search principle - http://trac.syr.edu/immigration/library/P1075.pdf