I would appreciate help with the following three:-
13 across "Producer whose films include Unbreakable and Snow White and The Huntsman"(3,6) S?M ?E?C?R.
17 across "Political doctrine named after one of its two originators" (7)
M?R?I?M
28 down"Antonio ?A?G?S actor who played Huggy Bear in the Starsky and Hutch TV series"