Perhaps you should try some spelling variations:
"advanced simulation in computer program" » "advanced modulation in computer program" (Expand search), "advanced calculation in computer program" (Expand search), "advanced simulation and computer program" (Expand search), "advanced simulation _ computer program" (Expand search)
"using population from python programming" » "aging population from python programming" (Expand search), "ageing population from python programming" (Expand search), "young population from python programming" (Expand search), "using populations from python programming" (Expand search), "using population from pathogen programming" (Expand search), "using population from anthony programming" (Expand search)

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("advanced simulation in computer program") OR ("using population from python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"advanced simulation in computer program\") OR (\"using population from python programming\"))".
• Removing quotes may allow a broader search: (( advanced simulation in computer program ) OR ( using population from python programming )).
• Adding a wildcard symbol may retrieve word variants: (("advanced simulation in computer program") OR ("using population from python programming"))*.