The Wikipedia article about bias against left-handed people states that
In Vietnam, schools officially require students to write with their right hands, and some teachers of Grade 1 (when writing is taught) would implement that rule by deducting points from tests written by the left hand. The Civic Education textbook for grade 7 mentions a student thanking her old teacher for helping her write with her right hand, and stopping her from using her left hand to write.
Is this claim correct? No citation is provided. I haven't been able to find copies or other discussions of the Vietnamese "Civic Education textbook for grade 7" online, nor any other references to support this.
This question and a recent news story sparked my interest in this.