I have just set my keyboard to use a "Bosnian" keyboard (US keyboard with Bosnian Letters). The keyboard map shows that a number of different characters should be available on some keys beyond the usual <key> and SHIFT/<key>. For example Preview on the keyboard settings page (System Settings->Input Devices->Layouts) shows the keycap for the 4th key to the right of the LSHF as a square arranged like this:
V `
v @

But I can only get "v" and "V". I assume that the "`" and "@" can be produced by using the ALT or SHIFT or <whatever> keys. How can I get them?

Thanks - jon