Gaya APA

ASTM, . (1997). ASTM D 2521 - 76 ; ASTM D 2521 - 76 (Reapproved 2002) Standard specification for asphalt used in canal, ditch and pond lining . : ASTM.

Gaya MLA

ASTM, . "ASTM D 2521 - 76 ; ASTM D 2521 - 76 (Reapproved 2002) Standard specification for asphalt used in canal, ditch and pond lining". : ASTM, 1997. Diorama.