both! when it comes to physical books, usually sa tiktok live ko sila nabibili or sa shopee (just make sure na orig, na experience ko kasing dupe and fake huhu hassle pa iparefund thats why i prefer kapag live sell kapag online ako bumibili) AND OFC FULLY BOOKED depends nalang kung swerte makakita ng desire mong libro mwhehe + i haven't bought anything pa sa booksale but i think naman meron din don, u should be patience lang siguro,, na parang naghuhukay ka ng hidden gems (which is true)

AND SA ONLINE iba-iba site anon eh, but try mo sa https:// manybooks.net, most of the classic meron sya but sometimes kapag may gusto akong basahin nagpupursigi akong hanapin site by researching t___t doble kayod but worth it hehehhe