TEXTBOOK: CK 12 EARTH SCIENCE for HIGH SCHOOL
DESONIE, D. (2012). EARTH SCIENCE FOR HIGH SCHOOL. RETRIEVED MAY 23, 2018 FROM:
https://www.ck12.org/book/CK-12-Earth-Science-For-High-School/
DESONIE, D. (2012). EARTH SCIENCE FOR HIGH SCHOOL. RETRIEVED MAY 23, 2018 FROM:
https://www.ck12.org/book/CK-12-Earth-Science-For-High-School/