user3624: At the moment we have a couple of tags dealing with literature in different ways. The most common ones are book-recommendation and literature, where the first one deals specifically with recommendations for books while the other one is broader (but seldomly used). However, we also have scientific-literature and literature-search. 
To me, these latter two should be synonyms to literature, since the first one is implied at the site (we are dealing with scientific literature) and most literature questions is dealing with literature searches either way (asking for articles, how to search for sets of articles, what books to look at etc). However, I cannot suggest these synonyms (and almost nobody would be able to vote for them), so I suggest that one of the moderators should merge the tags. Having book-recommendation and literature as the main tags should be sufficient for the site at the moment.

user25568: Absolutely agree.
plus IMO it is good decision to keep 2 separate tags for book-recommendation and literature; because in spite of a grey-zone between the 2 (actually books are subset of literature) , they would have some practical difference. We commonly look for (1) books when we want to know the basics, the principles, and the brief, ultimate declaration-statement cumulated from many researches. On other hand (2) literatures excluding book, which may be (2)A. Research-papers / journals; pieces of close-ups of research (what exactly they have did, in details) or (2)B. Data-books, though books, a different sort of book (probably no one would 'recommend' as a basic book, so I'm putting them in second category), such as a regional flora or the CRC-handbook  or that type of things. 

3624: <p>At the moment we have a couple of tags dealing with literature in different ways. The most common ones are <a href="https://biology.stackexchange.com/questions/tagged/book-recommendation" class="post-tag" title="show questions tagged &#39;book-recommendation&#39;" rel="tag">book-recommendation</a> and <a href="https://biology.stackexchange.com/questions/tagged/literature" class="post-tag" title="show questions tagged &#39;literature&#39;" rel="tag">literature</a>, where the first one deals specifically with recommendations for books while the other one is broader (but seldomly used). However, we also have <a href="https://biology.stackexchange.com/questions/tagged/scientific-literature" class="post-tag" title="show questions tagged &#39;scientific-literature&#39;" rel="tag">scientific-literature</a> and <a href="https://biology.stackexchange.com/questions/tagged/literature-search" class="post-tag" title="show questions tagged &#39;literature-search&#39;" rel="tag">literature-search</a>. </p>

<p>To me, these latter two should be synonyms to <a href="https://biology.stackexchange.com/questions/tagged/literature" class="post-tag" title="show questions tagged &#39;literature&#39;" rel="tag">literature</a>, since the first one is implied at the site (we are dealing with scientific literature) and most literature questions is dealing with literature searches either way (asking for articles, how to search for sets of articles, what books to look at etc). However, I cannot suggest these synonyms (and almost nobody would be able to vote for them), so <strong>I suggest that one of the moderators should merge the tags</strong>. Having <a href="https://biology.stackexchange.com/questions/tagged/book-recommendation" class="post-tag" title="show questions tagged &#39;book-recommendation&#39;" rel="tag">book-recommendation</a> and <a href="https://biology.stackexchange.com/questions/tagged/literature" class="post-tag" title="show questions tagged &#39;literature&#39;" rel="tag">literature</a> as the main tags should be sufficient for the site at the moment.</p>
 25568: <p>Absolutely agree.</p>

<p>plus IMO it is good decision to keep 2 <em>separate</em> tags for <a href="https://biology.stackexchange.com/questions/tagged/book-recommendation" class="post-tag" title="show questions tagged &#39;book-recommendation&#39;" rel="tag">book-recommendation</a> and <a href="https://biology.stackexchange.com/questions/tagged/literature" class="post-tag" title="show questions tagged &#39;literature&#39;" rel="tag">literature</a>; because in spite of a grey-zone between the 2 (actually books are subset of literature) , they would have some practical difference. We commonly look for <strong>(1)</strong> <em>books</em> when we want to know the basics, the principles, and the brief, ultimate declaration-statement cumulated from many researches. On other hand <strong>(2)</strong> literatures excluding book, which may be <strong>(2)A.</strong> <em>Research-papers / journals</em>; pieces of close-ups of research (what exactly they have did, in details) or <strong>(2)B.</strong> <em>Data-books</em>, though books, a different sort of book (probably no one would 'recommend' as a basic book, so I'm putting them in second category), such as a regional <a href="https://en.wikipedia.org/wiki/Flora_(publication)" rel="nofollow noreferrer">flora</a> or the <a href="https://en.wikipedia.org/wiki/CRC_Handbook_of_Chemistry_and_Physics" rel="nofollow noreferrer">CRC-handbook</a>  or that type of things. </p>
