"the third important" is a correct and usable phrase in written English.
For example, "The third important step in making bread is to let the dough rise."
The third important group, RΔHv/¯¯¯CEv, has less influence.
The third important piece of suburban etiquette involves your home.
The que is the third important abstract data type (ADT).
The third important step is to match the battery to the job.
The third important outcome, on how well the protection lasts, will not be known until 2014.
The third important component of a rigorous economic capital allocation approach is capital measurement per se.
The third important ink was an iron gall, or chemical, ink.
Meanwhile, my brother, his eyes glazed and his conversation repetitive, took advantage of the third important Super Bowl tradition: drinking.
"The third important issue for today is to create a firewall around economies [that] are in difficulty".
Finally, the third important player is hardware, which makes possibility the Virtual Reality navigation in many different environments.
The third important property is what is referred to as the distributive property, namely the fact that convolution distributes over addition.
