I have myself ordered lots of English-language books on different
agricultural and aquaculture subjects from online booksellers in the
United Kingdom. I have usually ended up using amazon.co.uk
(http://www.amazon.co.uk/), as they seem to have the most extensive
availability - they even direct you to sellers of used books.
Amazon.co.uk are able to ship any country in the world.
Another excellent bookseller is WHSmith (WHSmith.co.uk), but their
prices are usually a bit higher than Amazon.co.uk's. WHSmith also
ship books worldwide.
I have compiled a list of links to these shops' category listings of
books in each of the mentioned subjects.
http://www.amazon.co.uk/exec/obidos/tg/browse/-/922504/ (973 titles available)
http://www.whsmith.co.uk/whs/Go.asp?BIC=bTVH (enter "poultry" in the
search box - 31 titles are available)
Go to this category and enter "catfish" in the "Search in Fisheries"
field - the search returns 7 titles, of which 2 are available for
ordering: "Recent Developments in Catfish Aquaculture" and "Channel
Catfish Farming Handbook"
http://www.amazon.co.uk/exec/obidos/tg/browse/-/271780/ (201 titles available)
http://www.whsmith.co.uk/whs/Go.asp?BIC=bVGPC (flowers, 198 titles)
http://www.whsmith.co.uk/whs/Go.asp?BIC=bVGPS (shrubs and threes, 138
General farming procedures:
agriculture & farming, 1816 titles)
science, 961 titles)
agriculture, 318 titles)
http://www.whsmith.co.uk/whs/Go.asp?BIC=bTV (this category contains
all Agriculture & farming titles - currently 3382 in total)
When you find the books you want, I'll suggest that you use the
BookBrain service at http://www.bookbrain.co.uk/advsearch.asp to
determine prices at different bookstores. You might find that the
books you want can be obtained for a lower price at some other
bookstore than those I have listed here.
I hope this answer provides the information you need. If not, please
request an answer clarification.