If you are citing several works published by the same author in the same year, use lower case letter directly after the year to separate them. The same year-letter combination is used in both the in-text reference and the reference list.
| In-text reference | |
|---|---|
| (Ljungberg, 2002a, 2002b) | Ljungberg has investigated the habitat needs of threatened ground living beetle species in Sweden (2002a, 2002b)… |
| Reference list |
|---|
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​Ljungberg, H. (2002a). Bete, störning och biologisk mångfald i odlingslandskapet: Hotade skalbaggar i öländska torrmarker (Meddelande 2002:20). Länsstyrelsen Kalmar län. Ljungberg, H. (2002b). Våra rödlistade jordlöpares habitatkrav. Entomologisk tidskrift, 123(4), 167-185. |