Tucson Unified School District board members approved a list of supplemental books for the recently approved culturally relevant U.S. history program with a 3-2 vote.

Criticism of the book list for the courses has come from some activists saying there are no Chicano authors included in the Mexican-American history portion of the program.

Adelita Grijalva, board president, said the list is only the beginning, and that more books may be added as the school year progresses.

"My understanding is that more books are coming forward," she said. "There are supplementary texts. They're not an exclusive list."

Mark Stegeman said he voted against the curriculum because he felt the approval process was rushed.

"It was not at all about the particular list of books," Stegeman said. "It was about the process. Both generally that the process for this curriculum has been so rushed. And in particular that we had just received this list of books."

TUSD has faced national scrutiny since ending the Mexican-American Studies program nearly two years ago. The new program's courses include both African-American and Mexican-American histories.