Did someone call for ANATOMY LESSONS?!
Seriously. Dude. Reference pictures are your friend.
The abdomen's too long, not to mention skeletal (Unless you're Pro-An, this is a problem). The ribcage is nonexistant, the boob that we can see is anatomically incorrect, what with the nipple being in the wrong place, along with the center of gravity for the breasts.
The legs are sausages, having near no definition or differentiation between thighs and calves beyond the blurb of hamstrings on the back. The feet are definitely the worst extremities, with a socklike sillhouette that doesn't fit a boot-covered foot at all.
The ass is probably a seperate entity, what with the rest of the body being anorexic in the extremes(and thus the fat percentage is depleted EVERYWHERE).
The arms are decent, except for the fact that the right hand seems to be a hooklike stub welded to the gun, which seems to be spewing fire, even though it seems to be an automatic weapon(thus not a flamethrower, what with its lack for fuel tanks and such).
The hair's a little funky, due to the figure seeming to be rapidly moving forward and its staying rather plastered to her form. But I'll pass it off to being matted from sweat and stuff...
The face is mysterious, what with the dramatic shadowing, but, like the hindquarters, doesn't seem to fit the rest of the body.
So, overall, the face and arms are the best part of this. The lower half of the body is prolly the worst part, due to its sausage physics
My suggestion is to get some better, WHOLE references, because it looks like you're picking and choosing what parts to use on a drawn figure. ALSO KEEP IN MIND that some reference picture have the subjects at different distances, so you'll want references that are within about the same distance when they were depicted/photographed.
And that's all I got, other than the people who simply stare at various body parts and nothing else are rubes and you shouldn't trust them to get a good idea of the reception of your art on the whole...