(to be) on an organization's list, for example of people who are available for a particular type of work :
We have very few nurses on our books at the moment.
Most of the houses on our books are in the north of the city.
(to be) on an organization's list, for example of people who are available for a particular type of work :
We have very few nurses on our books at the moment.
Most of the houses on our books are in the north of the city.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005