APA
Wiiliam D Clark, . (2019). Easy Math Step By Step. United State Of America: McGraw Hill Education.
Chicago
Wiiliam D Clark, . 2019. Easy Math Step By Step. United State Of America: McGraw Hill Education.
Harvard
Wiiliam D Clark, . (2019). Easy Math Step By Step. United State Of America: McGraw Hill Education.
MLA
Wiiliam D Clark, . Easy Math Step By Step. United State Of America: McGraw Hill Education. 2019.