San Marino legislation is now searchable through Global-Regulation.com. The laws are converted to PDF and then translated from Italian into English.
Here’s an example search for “stamp taxes”: https://www.global-regulation.com/search.php?year&country=San+Marino&province&start&q=stamp+taxes&advanced=false. San Marino has quite a few laws about stamps and is a favoured country of stamp collectors.
Here’s another example for banks: https://www.global-regulation.com/search.php?year&country=San+Marino&province&start&q=bank&advanced=false.
As with all Global-Regulation searches, clicking the search result sends the user to the official publication.