regarding formatting for the american journal of botany i am

regarding formatting for the american journal of botany, i am confued on what to when you have two journal references by the same authors published in the same year. the website states:

List works by the same author(s) chronologically, beginning with earliest date of publication. Spell out all author(s)’ names. Use “a”, “b” (determined alphabetically) for works with the same author(s) and year citation. http://cms.botany.org/file.php?file=SiteAssets/publications/ajb/ajb_Lit_Cited_Instructions.pdf

below are my two sources, how do use the \"a\" \"b\" in the literature cited page and how do i use \"a\" \"b\" for citing in the text?

MASTERS, J. AND S. EMORY. 2015. Leaf Litter Depth has only a Small Influence on Ranunculus ficaria (Ranunculaceae) Biomass and Reproduction. American Midland Naturalist 173: 30-37.

in text cite: (Masters and Emory, 2015)

MASTERS, J. AND S. EMORY. 2015. The showy invasive plant Ranunculus ficaria facilitates pollinator activity, pollen deposition, but not always seed production for two native spring ephemeral plants. Biological Invasions 17: 2329-2337.

(Masters and Emory, 2015)

please write out how they should look in regards to \"a\" \"b\"

Solution

-In the given scenario, if two articles are needed to be cited that are published in the same year and by the same author, the following is the procedure to write them out -

MASTERS, J. AND S. EMORY. 2015a. Leaf Litter Depth has only a Small Influence on Ranunculus ficaria (Ranunculaceae) Biomass and Reproduction. American Midland Naturalist 173: 30-37.

MASTERS, J. AND S. EMORY. 2015b. The showy invasive plant Ranunculus ficaria facilitates pollinator activity, pollen deposition, but not always seed production for two native spring ephemeral plants. Biological Invasions 17: 2329-2337.

- And in the text they can be cited as (Masters and Emory, 2015a) and (Masters and Emory, 2015b).

- Many journals follow the same rule in citing these type of twin articles.