APA

Gopalakrishnan (K R), . (1991). Machine Drawing Ed.5. : .

Chicago

Gopalakrishnan (K R), . 1991. Machine Drawing Ed.5. : .

Harvard

Gopalakrishnan (K R), . (1991). Machine Drawing Ed.5. : .

MLA

Gopalakrishnan (K R), . Machine Drawing Ed.5. : . 1991.