Use "en" before the book's title

Error²Federal courts, Illinois courts21st and 22nd editions

A Mexican book cite names the chapter first and the book second, joined by the Spanish preposition, which marks the second title as the whole rather than another part.¹

1. 1T2.28 Mexico; T2.27 Mexico.
2. 2An error: the rule in note 1 allows one form, and this is not it.