Mass. Gen. Laws ch. 108A, § 22: Partner's right to formal accounting

Section 22. Any partner shall have the right to a formal account as to partnership affairs:

(a) If he is wrongfully excluded from the partnership business or possession of its property by his co-partners,

(b) If the right exists under the terms of any agreement,

(c) As provided by section twenty-one,

(d) Whenever other circumstances render it just and reasonable.