William H. Shea, "The Qinah Structure of the Book of Lamentations, Biblica 60.1 (1979): 103-107.

Shea argues that the "qinah" meter, identified as 3:2 (in terms of stressed accents), has been applied to the composition of Lamentations as a whole. The acrostically divided chapters fall into two groups, according to whether they employ poetic units in multiples of three (stanzas of three cola each)--as in the first three poems--or in multiples of two--as in the final two chapters.