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Comment
. 1994 Aug;309(6953):540.
doi: 10.1136/bmj.309.6953.540a.

Experimental and observational methods of evaluation

N Black
Comment

Experimental and observational methods of evaluation

N Black. BMJ. 1994 Aug.
No abstract available

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    Sheldon TA. Sheldon TA. BMJ. 1994 Jul 16;309(6948):142-3. doi: 10.1136/bmj.309.6948.142. BMJ. 1994. PMID: 8044089 Free PMC article. No abstract available.

References

    1. BMJ. 1994 Jul 16;309(6948):142-3 - PubMed

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