How do I cite same reference multiple times in a paper? I am writing a report on CPUs and I need to constantly need to cite technical information from a single reference multiple times throughout the report, specifically the datasheet for an Intel processor. Should I be citing my reference every time I cite some information from the datasheet like this?


  This sentence has some information. [1]
  ....4 pages later...
  This sentence has more information. [1]


Or should I only need to reference the data sheet once? I've searched around and it seems like it's a bad thing to cite the same reference multiple times, but I'm not sure how to handle this.
The most important principle to follow is that the source of the information that you are discussing should always be clear to a reader.  I thus find the following citation heuristics useful:


When you present a single statement in isolation, as in your example, each such statement should be individually cited.
When you are presenting a few statements in a chain, the first should have a citation, and the others be connected by prose.  For example:


  The Toast-o-matic processor has an unusual 19 bit word size [1].  It is also notable for its grilled cheese coprocessor and unusually high power demands.  Strong cooling is required, as the specifications note that its browning module is capable of attaining temperatures of more than 500F.

For larger contiguous blocks, such as a full paragraph or section, there should be an explicit delineation of the region covered by the citation.  For example:


  In this subsection, we briefly review the specifications of the Toast-o-matic processor[1].  The Toast-o-matic processor has an unusual 19 bit word size.  It is also notable...