**Acknowledgements**

The leadership and institutional support of Eng. José Guillermo Cárdenas López, Director of the National Technological of Mexico Campus Tijuana, is hereby acknowledged for all the support provided to make the scientific research project possible. Likewise, to achieve the Distinction of the National System of Researchers at Level 2, by the National Council of Science and Technology (CONACYT) of the Federal Government of Mexico.

Likewise, I am grateful for the support of fellow researchers internationally in promoting the QHS methodology for more than 10 years (since 2010). Dr. Rodolfo Arce Portuguez, Dr. Mayela Cubillo Mora, Dr. Federico Li Bonilla, Dr. Gonzalo Araya, Dr. Gabriel Silva from Costa Rica, Dr. Erico Wulf from Chile, Dr. Juan Fernando Alvarez from Colombia, Dr. Daniel Francisco Nagao Menezes from Brazil, Dr. Luis Cerdá from Spain and Dr. Dante Avaro from Argentina.

> Sincerely Dr. Rodolfo Martinez-Gutierrez
