English for Hotel Management

I'm about to teach English to a group training for Hotel Management (through GRETA). The students are all good English speakers already and want to know about English for writing contracts between travel agents and the hotel for example which is definitely deeper than I've gone in the past.

Does anyone out there know of any resources, book, internet etc that would be useful? I have a selection of stuff like High Season and Be my Guest which work ok for reception but would like a text that's a bit more substantial.

Many thanks.