Gaya APA

ASTM, . (1997). ASTM D 4750 - 87 (reapproved 1993) ; ASTM D 4750 - 87 (Reapproved 2001) Standard test method for determining subsurface liquid levels in a borehole or monitoring well (observation well) . : ASTM.

Gaya MLA

ASTM, . "ASTM D 4750 - 87 (reapproved 1993) ; ASTM D 4750 - 87 (Reapproved 2001) Standard test method for determining subsurface liquid levels in a borehole or monitoring well (observation well)". : ASTM, 1997. Diorama.