Several other mechanisms were proposed as well, each with their own problems.

Two mechanisms have been proposed to account for this movement.

The two mechanisms proposed are very similar and the reality is most likely a combination of both.

Several mechanisms have been proposed for this relationship, but none are widely agreed upon.

Other less than comprehensive mechanisms have been proposed but not adopted.

Four different mechanisms are proposed for the next step, oxygen capture.

Two mechanisms have been proposed, dependent on the location of the water in the active site.

The original mechanism proposed by Phillips was more recently revised.

Other mechanisms have been proposed to explain the utility of altitude training.

Various mechanisms have been proposed to explain the cause of Heinrich events.