return {
    'basic-transport-belt',
    'transport-belt',
    'fast-transport-belt',
    'express-transport-belt',
    'turbo-transport-belt',
    'ultimate-transport-belt',
    'basic-underground-belt',
    'underground-belt',
    'fast-underground-belt',
    'express-underground-belt',
    'turbo-underground-belt',
    'ultimate-underground-belt',
    'small-electric-pole',
    'medium-electric-pole',
    'medium-electric-pole-2',
    'medium-electric-pole-3',
    'medium-electric-pole-4',
    'big-electric-pole',
    'big-electric-pole-2',
    'big-electric-pole-3',
    'big-electric-pole-4',
    'substation',
    'substation-2',
    'substation-3',
    'substation-4',
    'electric-mining-drill',
    'bob-mining-drill-1',
    'bob-mining-drill-2',
    'bob-mining-drill-3',
    'bob-mining-drill-4',
    'bob-area-mining-drill-1',
    'bob-area-mining-drill-2',
    'bob-area-mining-drill-3',
    'bob-area-mining-drill-4',
    'burner-mining-drill',
    'steam-mining-drill',
    'pumpjack',
    'bob-pumpjack-1',
    'bob-pumpjack-2',
    'bob-pumpjack-3',
    'bob-pumpjack-4',
    'water-miner-1',
    'water-miner-2',
    'water-miner-3',
    'water-miner-4',
    'water-miner-5',
    'car',
    'tank',
    'bob-tank-2',
    'bob-tank-3',
    'spidertron'
}
