Australian publisher Cengage Learning Asia recalled textbooks used in Victoria containing the "cow's tongue line" map.

The Chinese map depicted in the book "Advanced Chinese Language Course: Chinese Language, Culture and Society" contains the "cow's tongue line" - claiming unilaterally outlined China to claim sovereignty over most aspects

"We apologize to readers for this carelessness", the publisher of Cengage Learning Asia on March 25 released a statement, announcing that they had requested the book recall and sought a remedy.

Although this textbook is not listed by the Victorian educational administration as mandatory course material, it is being used at at least 11 schools in the state, including some reputable private schools.

A Cengage spokesperson explained that initially the manuscript contained a different map, without the "cow's tongue line", but editorial editors replaced it because the copyright holders of the maps could not be identified.

"It is very misleading to show the" cow's tongue line "as a legitimate map of China and the region in a textbook," said Professor Rory Medcalf, head of the University's National Security School.

"Having it appeared in textbooks in Australia is not only inconsistent with the sensitivities of most regions, but also goes against international law and Australian government policy," the professor added.