Ask your private teacher or chamber music coach for advice, or check out these websites below:
This online chamber music database has customizable search options like nationality and gender of the composer, ensemble type, key signature, and dates of composition. The listing for each work includes helpful tools like links to scores and recordings and a glossary of terms.
This website gives you free access to thousands of pieces of music in the public domain (not under copyright). The site is fully searchable, and you can also browse by category including an instrumentation category.
This website has a wonderful feature that allows you to search for pieces of music by plugging in the specific instrumentation (for ensembles including at least one double reed instrument).
Educational Music Service
This is a fantastic resource for all of your sheet music needs, including chamber music. Their staff is extremely helpful, especially at finding obscure pieces.