This test illustrates a use case for the following rule, discussed on the Zotero forums:

  "When different groups of authors with the same first author and date 
  occur, they should be cited thus: (Able, Baker & Charles 1986a; Able, 
  David & Edwards 1986b), then subsequently abbreviated to (Able et al. 
  1986a; Able et al. 1986b)."

  "Italicized letters 'a', 'b', 'c', etc., should be added to the date of 
  papers with the same first authorship and year"

The test illustrates that the first rule can be satisfied with the CSL 0.8
feature set, and the second using the year-suffix text variable introduced
in CSL 0.9.  It differs slightly from the example given by the poster
(asplundj) in that the cites do not include author initials, but this conforms
to the cited style guide.


The discussion can be found at: 
  http://forums.zotero.org/discussion/5290/collapse-year-suffix/

The style guide containing the rule quoted above can be found 
at:
  http://www.wiley.com/bw/submit.asp?ref=0269-8463&site=1


The point in all of this for implementers is that evaluation of 
an in-text key for disambiguation purposes should be based on the 
subsequent form of the cite, even if it occurs only once in the 
text.


Frank Bennett
2009-04-14



>>===== MODE =====>>
citation
<<===== MODE =====<<



>>===== RESULT =====>>
(Baur, Fröberg, Baur, et al. 2000<i>a</i>; Baur, Schileyko &#38; Baur 2000<i>b</i>; Doe 2000)
<<===== RESULT =====<<


>>===== CSL =====>>
<style 
      xmlns="http://purl.org/net/xbiblio/csl"
      class="note"
      version="1.0">
  <info>
    <id />
    <title />
    <updated>2009-08-10T04:49:00+09:00</updated>
  </info>
  <citation 
         disambiguate-add-year-suffix="true"
         et-al-min="3"
         et-al-subsequent-min="1"
         et-al-subsequent-use-first="1"
         et-al-use-first="3">
    <layout delimiter="; " prefix="(" suffix=")">
      <names variable="author">
        <name and="symbol" delimiter=", " delimiter-precedes-last="never" form="short" />
      </names>
      <date prefix=" " variable="issued">
        <date-part name="year" />
      </date>
      <text font-style="italic" variable="year-suffix" />
    </layout>
  </citation>
</style>
<<===== CSL =====<<


>>===== INPUT =====>>
[
    {
        "author": [
            {
                "family": "Baur",
                "given": "Bruno"
            },
            {
                "family": "Fröberg",
                "given": "Lars"
            },
            {
                "family": "Baur",
                "given": "Anette"
            },
            {
                "family": "Guggenheim",
                "given": "Richard"
            },
            {
                "family": "Haase",
                "given": "Martin"
            }
        ],
        "container-title": "Nordic Journal of Botany",
        "id": "ITEM-1",
        "issued": {
            "date-parts": [
                [
                    "2000"
                ]
            ]
        },
        "page": "119-128",
        "title": "Ultrastructure of snail grazing damage to calcicolous lichens",
        "type": "article-journal",
        "volume": "20"
    },
    {
        "author": [
            {
                "family": "Baur",
                "given": "Bruno"
            },
            {
                "family": "Schileyko",
                "given": "Anatoly A."
            },
            {
                "family": "Baur",
                "given": "Anette"
            }
        ],
        "container-title": "Journal of Molluscan Studies",
        "id": "ITEM-2",
        "issued": {
            "date-parts": [
                [
                    "2000"
                ]
            ]
        },
        "page": "285-289",
        "title": "Ecological observations on _Arianta aethiops aethiops_ (Helicidae), a land snail endemic to the South Carpathian mountains, Romania",
        "type": "article-journal",
        "volume": "66"
    },
    {
        "author": [
            {
                "family": "Doe",
                "given": "John"
            }
        ],
        "container-title": "Journal of Irreproducible Results",
        "id": "ITEM-3",
        "issued": {
            "date-parts": [
                [
                    "2000"
                ]
            ]
        },
        "page": "5-7",
        "title": "Some bogus title",
        "type": "article-journal",
        "volume": "666"
    }
]
<<===== INPUT =====<<


>>===== VERSION =====>>
1.0
<<===== VERSION =====<<