APA (7th ed.) Citation

<KREBS, R. D. &. R. W. Highway materials. McGraw-Hill Book Co.

Chicago Style (17th ed.) Citation

<KREBS, Robert D & R.D. Walker>. Highway Materials. McGraw-Hill Book Co.

MLA (8th ed.) Citation

<KREBS, Robert D & R.D. Walker>. Highway Materials. McGraw-Hill Book Co.

Warning: These citations may not always be 100% accurate.