If the compound noun has a hyphen or hyphens, the -s usually goes at the end of the noun, such as in secretaries-general, passers-by and fathers-in-law. To make the possessive form, simply add an apostrophe -s to the end...
THINKING: We just don’t put enough time into it in the classroom. So several years ago I created a poster to remind my students to think while they are writing. It worked for a while, and then like so many strategies after a while it went by the wayside. Recently after conferencing ...
Probabilities for character sequences such as 't (which can be used to automatically add an apostrophe before the character ‘t’) must be established a-priori. Each language model utilizes an approximate trie 13 (see FIGS. 2A and 2C) or a probabilistic trie 33 (see FIGS. 2B and 2D) ...